Title: Structural Computable Analysis

Speaker: Timothy McNicholl, Iowa State University

Date and Time: November 11, 2016, Friday, 1:00 -2:00 pm

Place:   Rome 206

Abstract:  Computability theory is the mathematical study of the limits and potentialities of discrete computing devices.  Computable analysis is the theory of computing with continuous data such as real numbers.  Computable structure theory examines which computability-theoretic properties are possessed by the structures in various classes such as partial orders, Abelian groups, and Boolean algebras.  Until recently computable structure theory has focused on classes of countable algebraic structures and has neglected the uncountable structures that occur in analysis such as metric spaces and Banach spaces.  However, a program has now emerged to use computable analysis to broaden the purview of computable structure theory so as to include analytic structures.  The solutions of some of the resulting problems have involved a delicate blend of methods from functional analysis and classical computability theory.  We will discuss progress so far on metric spaces and Banach spaces, in particular $\ell^p$ spaces, as well as open problems and new areas for investigation.

Bio: Tim McNicholl received his Ph.D. from The George Washington University in 1995.  He pursues research projects that involve a mixture of computability theory, complex analysis, and functional analysis and enjoys working with mathematicians from fields other than logic.  He has been an Associate Professor of Mathematics at Iowa State University since 2012 where he has directed the redesign of the precalculus curriculum.  HIs work on precalculus curricula helped the Iowa State University Mathematics Department win an award for an Exemplary Program or Achievement in a Mathematics Department from the American Mathematical Society in 2015.

Title: Fixed point theorem and solutions for the Nonlinear Schrödinger equation.

Speaker: Luiz Gustavo Farah, GWU

Date and Time:  October 7, 2016, Friday, 1:00 -2:00 pm

Place:   Rome 206

Abstract: In 1933, the Austrian physicist Erwing Schrödinger was awarded the Nobel Prize in Physics. Among its notable scientific contributions he formulated one of the fundamental equations of quantum physics, now known as Schrödinger equation. In this talk, we will develop mathematical tools to prove the existence of solutions for this equation in a special case. Our exposition will be self contained and all of the mathematics needed (most of it well-known) will be introduced en route.

Bio: Luiz Gustavo Farah has been a professor of mathematics at the Federal University of Minas Gerais - UFMG (Brazil) since 2010 and is currently a visiting researcher scholar at the George Washington University. He graduated from IMPA (Brazil) with a PhD in Mathematics in 2008. During 2009 he was a postdoctoral researcher in the Department of Mathematics at the University of California, Santa Barbara. His research interests are in Harmonic Analysis and Partial Differential Equations and he has published several papers concerning the existence and asymptotic behavior of solutions to nonlinear dispersive models.

Spring 2016

Speaker: VLADIMIR VERSHININ (Universite de Montpellier, France)

Time: Tuesday, 4/26, 11am-12pm

Location: Media and Public Affairs B07

Title: BRAIDS AND HOMOTOPY GROUPS OF SPHERES

Abstract: We start with the geometrical (naive) definition of braids and then identify them with the fundamental group of configuration space of a manifold. The case of a surface is particular interesting. We recall some classical properties of braids and then pass to Brunnian braids. A braid is Brunnian if it becomes trivial after removing any one of its strands. We describe algebraically the group of Brunnian braids on a general surface, if the surface is not a sphere or projective plane. In these exceptional cases the group of Brunnian braids is described by an algebraic procedure together with the homotopy groups of a 2-sphere. If there will be time we shall speak about the graded Lie algebra of the descending central series related to Brunnian braid group. It is proved that this is a free Lie algebra and the set of free generators is described.

Bio: Vladimir Vershinin is a professor of mathematics at the Alexader Grothendieck Institute in Montpellier, France, and a researcher at the Sobolev Institute of Mathematics, Novosibirsk, Russia.

His interests in Mathematics include Algebraic Topology, and braid groups and their generalizations.

He had hold one year visiting position in Autonoma University of Barcelona, half year positions in the IHES, Paris, and the Poncelet Laboratory, Moscow.

Colloquium on Education in Mathematics

Speaker: Hyman Bass (University of Michigan)

Time: Friday, 4/15, 1-2pm

Location: Corcoran 101

Title: A vignette of mathematical practices in action

Abstract: Mathematical Practices are, essentially, the things you do when you do mathematics.  While they are emphasized in the Common Core, many teachers find it difficult to fully understand what they mean, or what they “look like.”  I will a present small piece of mathematics that arose from a question about fractions in third grade.  I will use this as a context to illustrate mathematical practices in action.  Here is the problem:  Suppose that s students want to equally share c cakes.
What is the smallest number, p(c, s), of cake pieces, needed to achieve this fair distribution?  We will derive a formula for p(c, s) and describe two different distribution schemes that achieve this, the “linear” and the “Euclidean” distributions.  The Euclidean distribution corresponds to the “Euclidean square tiling” of a c x s rectangle R, and we shall see that this square tiling is “isoperimetric” in the sense that it has smallest “perimeter” among all square tilings of R.  I will describe generalized version of this problem that is still open.

Bio: Hyman Bass is the Samuel Eilenberg Distinguished University Professor of Mathematics and Mathematics Education at the University of Michigan. He has served as President of the American Mathematical Society and the International Commission on Mathematical Instruction and as Chair of the National Academy of Sciences’ Mathematical Sciences Education Board, and of the AMS Committee on Education.  He is a member of the U.S. National Academy of Sciences, the American Academy of Arts and Sciences, the Third World Academy of Sciences, and the National Academy of Education.  In 2006 he received the U. S. National Medal of Science. His mathematical research spans various domains of algebra, notably algebraic K-theory and geometric group theory.  His work in education (largely with Deborah Ball) focuses mainly on mathematical knowledge for teaching, and on the teaching and learning of mathematical practices, such as reasoning and proving, and discerning and developing mathematical structure, in K-16 classrooms.

Math Department Colloquium -- Distinguished Speculative First of April Talk

Speaker: Scott Carter (University of South Alabama)

Time: Friday, 4/1, 1-2pm

Location: Corcoran 101

Title: The Role of Knots and Higher Dimensional Knots in Our
Understanding of the Quantum World

Abstract: According to the organizers of this event, this talk is meant to be speculative. The title alone satisfies that criterion! Yet, there seem to be at least two conflicting views of matter within our collective consciousness: the discrete and the continuous. Atoms, electrons, quarks, {\it etc.} are discrete particles while the meaning of particle in the first place has to do with a continuum --- the collection of representations of a (product of) unitary groups.

Since the time of Taite and Thompson (Lord Kelvin), and perhaps
earlier, matter was thought to be composed of knotted vortices in the
aether. Such a model is notoriously wrong, yet some aspects persist.
Knotted vortices can be created in the lab via the quantum hall
effect. The space-time trace of a particle is a string, and indeed a
$4$-dimensional view of the universe suggests that we should examine
the interactions of critical events.

So in this talk we start from toy models of particles that are created or annihilated, and that radiate and examine their critical interactions. Those aspects that you would like to consider ``the same," I will consider as isomorphic. And I will then study the isomorphism among them. To continue the speculation, we'll successively project figures to planes and see if the interactions among critical events therein resemble the physical models of reality.

The talk will be informed by pictures.

Bio: Dr. Carter graduated from Yale with a PhD in 1982. After that, he taught at University of Texas, Lake Forrest College and Wayne State University. In 1989, he became a professor of University of South Alabama. Since then, he has been active in the Mobile Math Circle and on Youtube. He was the chair of the Department of Math and Statistics of University of South Alabama from 2003 to 2010. He is currently a managing editor of Journal of Knot Theory and its Ramifications.

Speaker: Taduri Srinivasa Siva Rama Krishnarao (Indian Statistical
Institute, Bangalore Centre, and University of Memphis)

Time: Friday, 3/25, 1-2pm.

Location: Corcoran 101

Title: Proximinality for sums of closed subspaces

Abstract: In this talk we deal with the question of approximating minimizing sequences by sequence of proximinal vectors, for sums of closed subspaces. Motivated by some results of M. Feder and Pei-Kee Lin, we show that for a finite dimensional sub-space F  and a strongly proximinal subspace Y  of a Banach space X , F  + Y  is a strongly proximinal subspace of X . We also show the universality of the difficulty involved for sums of subspaces by showing that for any
infinite dimensional Banach space X  there exists an infinite dimensional space Z  containing an isometric copy of X  as a strongly proximinal subspace and a strongly proximinal subspace W  of Z  such that the sum X  +W  is a closed, proximinal subspace of Z  that is not strongly proximinal in Z .

Bio: Professor Taduri is currently Fulbright-Nehru Academic and Professional Excellence Scholar at the Department of Mathematical scienced, University of Memphis. A senior professor from the Indian Statistical Institute, a Fellow of the Indian Academy of Sciences, he is the current Head of the Indian Statistical Institute, Bangalore centre.
 

Special Colloquium

Speaker: Qing Han (Notre Dame)

Time: Tuesday, 3/8, 3:45-4:35pm

Location: Rome 204

Title: Isometric Embedding of 2-Dim Riemannian Manifolds in Euclidean 3-Space

Abstract: It is a classical problem to study whether any 2-dimensional Riemannian manifolds admit isometric embedding in the 3-dimensional Euclidean space. There are two versions of this problem, the local
version and the global version. The local version was presented by Schlaefli in 1973 and is still open. In this talk, we review both versions of the problem and present some recent results.

Bio: Professor Han got his PhD from Courant Institute in 1993. After that, he was a Dickson Instructor at University of Chicago for a year. He became a faculty member of University of Notre Dame in 1994. He was also a visiting member of Courant Institute and Max-Planck Institute for Mathematics, Leipzig. He was recognized by a Sloan Foundation Research Fellowship in 1999.

Speaker: Nikita Alekseev (GWU)

Time: Friday, 3/4, 1-2pm

Location: Corcoran 106

Title: Combinatorial and Probabilistic approaches in Comparative Genomics.

Abstract: The ability to estimate the evolutionary distance between extant genomes plays a crucial role in modern phylogenomic studies. When we say "evolutionary distance between two genomes on the same set of genes" we mean a number of genome rearrangements which transformed one genome into another in the course of evolution. In this talk we discuss how to find the evolutionary distance within different mathematical models. We demonstrate combinatorial and probabilistic approaches to the problem.

Bio: Dr. Nikita Alexeev is a postdoctoral researcher in Computational Biology Institute at the George Washington University. He graduated from St. Petersburg State University (Russia) with a PhD in Mathematics and Statistics in 2012. During 2008-2011 he was a visiting researcher in Bielefeld University, Germany. During 2011-2014 he was a researcher at the Chebyshev Laboratory, SPbSU. His research interests are Combinatorics, Graph Theory, Probability Theory and Computational Biology.

Speaker: Roman Sznajder (Bowie State)

Time: Friday, 2/26, 1-2pm

Location: Corcoran 106

Title: ENIGMA: Harnessing mathematics in cryptology

Abstract: ENIGMA was a German ciphering machine developed soon after WWI for commercial use. Shortly after, it was acquired by the German army and used for encrypting and decrypting military messages and orders.  We discuss the circumstances that led to the initial breaking of the Enigma code in 1932 by three young cryptologists: Rejewski, Różycki, and Zygalski from the Polish Cipher Office.  This was the first time when mathematics was systematically used in cryptography. Specifically, there were applications of permutation groups used to reconstruct the wiring of military Enigma and then to recover the daily keys and keys for individual messages. In the summer of 1939, when the outbreak of WWII was imminent, the Polish Cipher Office provided Allies with two copies of the Enigma machine and daily keys. Aided by these materials, the British immediately began working on breaking Enigma messages. Their office in Bletchley Park had access to human, engineering, and technological resources on an industrial scale.  The ability to read encrypted messages used by the German army—enabled by the breaking of the Enigma code—contributed to the shortening of WWII and, according to some estimates, spared several million lives.  With the British WWII archives sealed and Poland behind the Iron Curtain, the British Secret Service suppressed the knowledge about the role of Polish intelligence in breaking the Enigma
code for about thirty years. The heroic effort of three Polish cryptologists was virtually unknown to the world until the 1973 publication of a book by the French general Gustave Bertrand.  In this presentation, we will shed some light on mathematical methods, the events and people involved in the successful effort to break the Enigma code. Since the beginning of the US involvement in WWII (1942), there was a very close cooperation between the US and British intelligence. Two prominent American cryptologists, Drs. Solomon Kullback and Abraham Sinkov were involved in this project. Two high school friends, both obtained their doctorates from The Washington University (in 1934 and 1933, respectively). Dr. Sinkov was a full fledge cryptologist, while Dr. Kullback who, at a certain moment of his career, was on the faculty of The GWU, was a statistician by heart. Colonels Kullback and Sinkov are members of the Military Intelligence Hall of Fame.

Bio: Dr. Roman Sznajder is a professor of mathematics and Graduate Program Coordinator in Applied and Computational Mathematics at Bowie State University. He received his Ph.D. in applied mathematics in 1994 from University of Maryland, Baltimore County. His current research interests include nonlinear analysis, optimization and history of mathematics. He authored and co-authored 35 articles, presented his findings at various international conferences, and reviewed papers to
about 30 research journals.

Special Colloquium

Speaker: Alex Iosevich (University of Rochester)

Time: Thursday, 2/18, 3:45-4:35pm

Location: Rome 204

Title: Orthogonal bases and tiling: analysis, number theory and combinatorics

Abstract: In 1974 Bent Fuglede conjectured that if a set Omega is abounded domain in R^d, then the space L^2(Omega) has an orthogonalbasis of exponentials if and only if Omega tiles the space R^d bytranslation. Even though this conjecture was disproved by Terrance Tao in 2004 in dimensions 5 and higher, it is continuing to leadresearchers to fascinating connections and ideas that involve avariety of areas of modern mathematics. In this talk we will present asampling of these ideas and connections between them, as well as some recent developments in this fascinating field.

Bio: Alex Iosevich got his B.S. in Mathematics at the University of Chicago in 1989 and a Ph.D. in Mathematics at UCLA in 1993 under thedirection of Christopher Sogge. After a postdoctoral fellowship at McMaster University, he worked at Wright State University, Georgetown University and the University of Missouri. Iosevich is currently a Professor of Mathematics at the University of Rochester. He has
graduated 11 Ph.D. students and in 2015 he became a Fellow of the AMS.  Iosevich works in harmonic analysis, geometric combinatorics and additive number theory, with emphasis on connections between those areas.

Special Colloquium

Speaker: Carolyn Chun (US Naval Academy)

Time: Tuesday, 2/16, 3:45-4:35pm

Location: Corcoran 101

Title:  Inductive tools for graphs (and matroids)

Abstract:  In this talk, we consider inductive tools for graphs (and matroids) that preserve a kind of robustness, called connectivity.  In 1966, Tutte proved that every 3-connected graph (or matroid) other than a wheel (or whirl) has a single-edge deletion or contraction that is 3-connected.  Seymour extended this result in 1980 to show that, in addition to preserving 3-connectivity, we can preserve a given substructure, namely a 3-connected minor.  We present the long-running
project joint between the speaker, James Oxley, and Dillon Mayhew to obtain such results for graphs (and matroids) that are internally 4-connected.

Bio:  Carolyn Chun completed her PhD at Louisiana State University in 2009, advised by James Oxley.  She moved to New Zealand for three years to be a research postdoc at Victoria University of Wellington with Geoff Whittle.  She spent the following three years in London, as a research postdoc at Brunel University London with Steven Noble.  In
January 2016, Carolyn became an assistant professor in the math department at the US Naval Academy.  She loves graphs, matroids, delta-matroids, and traveling.

Speaker: Jonathan Katz (UMD)

Time: Thursday, Feb 11, 3:45-4:35pm

Location: Rome 204

Title: On the Nature of Mathematical Proofs: A Cryptographic Perspective

Abstract: Beginning in the mid-'80s, complexity theorists began radically revising the notion of what (mathematical) proof might entail, introducing and extending the ideas of using both randomness and interaction as part of the proof-verification process. Cryptographers took this one step further with the idea of *zero-knowledge proofs*, which are supposed to reveal "no information" beyond the validity of the theorem being proven.

We give an introductory survey of these fundamental and now-classical concepts, and conclude with a brief discussion of current research exploring their applications and extensions to the settings of secure distributed computation and verifiable outsourcing.

Bio: Jonathan Katz is a professor of computer science at the University of Maryland, and director of the Maryland Cybersecurity Center. He received an undergraduate degree in mathematics from MIT, and a PhD in computer science from Columbia University. His research interests lie broadly in the fields of cryptography, privacy, and science of cybersecurity, and he is a co-author of the widely used textbook "Introduction to Modern Cryptography." Katz was a member of the DARPA Computer Science Study Group from 2009-2010, and received a Humboldt Research Award in 2015. He currently serves on the steering committee for the IEEE cybersecurity initiative, as well as the State of Maryland Cybersecurity Council.

Speaker: Jonathan Katz (UMD)

Time: Friday, Jan 22, 3:45-4:45pm(rescheduled to Thursday Feb 11, 2016)

Location: Corcoran 106

Title: On the Nature of Mathematical Proofs: A Cryptographic Perspective

Abstract: Beginning in the mid-'80s, complexity theorists began radically revising the notion of what (mathematical) proof might entail, introducing and extending the ideas of using both randomness and interaction as part of the proof-verification process. Cryptographers took this one step further with the idea of *zero-knowledge proofs*, which are supposed to reveal "no information" beyond the validity of the theorem being proven.

We give an introductory survey of these fundamental and now-classical concepts, and conclude with a brief discussion of current research exploring their applications and extensions to the settings of secure distributed computation and verifiable outsourcing.

Bio: Jonathan Katz is a professor of computer science at the University of Maryland, and director of the Maryland Cybersecurity Center. He received an undergraduate degree in mathematics from MIT, and a PhD in computer science from Columbia University. His research interests lie broadly in the fields of cryptography, privacy, and science of cybersecurity, and he is a co-author of the widely used textbook "Introduction to Modern Cryptography." Katz was a member of the DARPA Computer Science Study Group from 2009-2010, and received a Humboldt Research Award in 2015. He currently serves on the steering committee for the IEEE cybersecurity initiative, as well as the State of Maryland Cybersecurity Council.

Fall 2015

Speaker: Paul Wedrich, University of Cambridge, UK

Title: Knot homologies and their deformations
Date and Time: November 13, 2015; 1:00–2:00 pm
Place: Government 101

Abstract: Knot homology theories are powerful generalizations of classical (and quantum) knot polynomials. Besides providing stronger invariants, these theories are often functorial under knot cobordisms and contain additional geometric information. I will start by introducing Khovanov homology, a paradigmatic example of a knot homology theory, and explain how it fits into the family of colored sl(N) knot homology theories. The goal of this talk is to explain how deformation techniques help to answer two important questions about this family: What relations exist between its members? What geometric information about knots and links do they contain? I will recall Lee's deformation of Khovanov homology and sketch how it generalizes to the case of colored sl(N) link homology. The result is a decomposition theorem for deformed colored sl(N) knot homologies, which leads to new spectral sequences between knot homologies and to new concordance invariants in the spirit of Rasmussen's  concordance invariant. Part of this is joint work with David E. V. Rose.

Short bio: Paul Wedrich obtained his PhD at the University of Cambridge in 2015 under the supervision of Jake Rasmussen. See

https://www.dpmms.cam.ac.uk/~pw360/Wedrich_cv.pdf

Speaker: Ajit Iqbal Singh, Indian National Science Academy

http://insaindia.org/detail.php?id=N99-1262

Title: Involutions and Trivolutions in Algebra and Analysis
Date and Time: November 6, 2015; 1:00–2:00 pm
Place: Government 101

Abstract: The natural involutions in a group of taking inverse and in the complex plane of taking reflection in the real axis are usually combined to give an involution in the algebra of complex functions on groups thus forcing it to be conjugate linear. For finite or infinite matrices, taking inverse is replaced by taking transpose, the reflection in the diagonal, which forces it to be an anti-homomorphism as well. This is the basis of the definition of an involution in Algebra. Certain restrictions, continuity conditions and scaling are called for when we pass on to the context of Functional Analysis or Harmonic  Analysis on groups, semi-groups and hypergroups. This opens up possibilities of many new involutions. However when we go to the biduals with Arens products, the availability starts being choosy. While the situation is fine for Arens regular algebras like C*-algebras,  surprisingly so,  it is  impossible to have any involution for biduals of  infinite amenable group algebras! Just like generalised inverses help in solving systems of equations, trivolutions T spring up as conjugate linear anti-homomorphisms T that are their own generalised inverses, i.e., T.T.T=T. This expository talk will give a gentle account including recent work by the speaker and her collaborators Mahmoud Filali and Mehdi Monfared.

Short bio at: https://en.wikipedia.org/wiki/Ajit_Iqbal_Singh

Speaker: Chris Laskowski, University of Maryland

http://www.math.umd.edu/~laskow/

Title: Towers of Babel:  What do probability, computer learning, combinatorial geometry, model theory, and neural networks have in common?
Date and Time: October 30, 2015; 1:00–2:00 pm
Place: Government 101

Abstract: This will be a rambling talk that highlights a very attractive, naturally occurring polynomial/exponential growth dichotomy that keeps getting discovered over and over in various fields of math and computer science. Absolutely no knowledge of any of the fields mentioned in the title is assumed.

Short bio: Chris Laskowski is a professor of mathematics at University of Maryland.  He is primarily interested in model theory, broadly defined.  In addition to mathematics, he has co-authored papers in computational geometry, economics, and protein chemistry.

Speaker: Alissa Crans, Loyola Marymount University (Los Angeles)

http://myweb.lmu.edu/acrans/

Title: Musical Actions of Dihedral Groups
Date and Time: October 16, 2015; 1:00–2:00 pm
Place: Government 101

Abstract: Can we hear an action of a group? Or a centralizer? In the same way it is possible to see group structure in a crystal, it is also possible to hear group structure in music.  We will investigate two ways that the dihedral group of order 24 acts on the set of major and minor chords and illustrate both geometrically and algebraically how these two actions are dual. Both actions and their duality have been used to analyze works of music as diverse as that of Beethoven and the Beatles.  (This is joint work with Thomas M. Fiore and Ramon Satyendra.)

Bio at: http://myweb.lmu.edu/acrans/CransCV.pdf

Spring 2015
speaker: Robert L. Devaney, Boston University

http://math.bu.edu/people/bob/

Title: Cantor and Sierpinski, Julia and Fatou: crazy topology in complex dynamics

Date and Time: Thursday, April 23, 2015 4:00–5:00pm
Place: Government Hall, Room 104

Abstract: In this talk, we shall describe some of the rich topological structures that arise as Julia sets of certain complex functions including the exponential and rational maps. These objects include Cantor bouquets, indecomposable continua, and Sierpinski curves. No real background in either complex dynamics or planar topology is necessary to follow this talk.

Short Bio at: http://math.bu.edu/people/bob/brief-vita.htm

Crowdmark: Online Collaborative Grading at GWU?

Crowdmark is a collaborative online grading and analytics platform that helps instructors and teaching assistants evaluate student work more effectively than ever before. Experiments involving thousands of students and more than a million exam pages have shown that Crowdmark cuts grading time in half. Audience members are encouraged to bring their laptops to participate in an interactive demonstration.

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Math Colloquium

(Distinguished Speculative First of April Talk)

Speaker: Scott Aaronson, MIT

http://scottaaronson.com/

Title: How Pervasive Is Incompleteness?

Date and Time: Friday, April 3, 2015 1:00–2:00pm

Place: Government Hall, Room 101

Abstract: I was asked to give a “speculative” math talk. So, I'll discuss the question of just how much “normal, finitary” math the Gödel incompleteness phenomenon might infest. I’ll first survey the types of independence and undecidability results that are known, and explain why in my view, none of them give a fully satisfactory answer. I’ll then speculate about the question, which I’m often asked, of whether the P vs. NP problem might turn out to be formally undecidable. Finally, I’ll discuss the Busy Beaver function, and its amazing ability to “concretize” questions of mathematical logic. I’ll mention some ongoing work with Adam Yedidia that aims to construct a small Turing machine whose (non-)halting is provably independent of the ZFC axioms.

Short Bio: Scott Aaronson is an Associate Professor of Electrical Engineering and Computer Science at MIT. He studied at Cornell and UC Berkeley, and did postdocs at the Institute for Advanced Study as well as the University of Waterloo. His research focuses on the capabilities and limits of quantum computers, and more generally on computational complexity and its relationship to physics.  His first book, Quantum Computing Since Democritus, was published in 2013 by Cambridge University Press. Aaronson has written about quantum computing for Scientific American and the New York Times, and writes a popular blog at www.scottaaronson.com/blog. He’s received the National Science Foundation’s Alan T. Waterman Award, the United States PECASE Award, and MIT's Junior Bose Award for Excellence in Teaching.

Math Colloquium

Speaker: Yanping Ma, Loyola Marymount University

http://myweb.lmu.edu/yma/

Title: Injury-initiated clot formation under flow: a mathematical model with treatment

Date and Time: Friday, March 27, 2015, 1:00–2:00pm

Place: Government Hall, Room 101

Abstract: When an individual at risk for forming a thrombus is treated with anticoagulant medication, the International Normalized Ratio (INR) must be measured regularly. We explore the conditions under which an injury-induced thrombus may form in vivo but not in vitro. We extend previous models and present numerical simulations that compare scenarios in which drug doses and flow rates are modified. Our results indicate that traditional INR measurements may not accurately reflect in vivo clotting times.

Short Bio: Yanping Ma obtained her PhD in math at Penn State University with minor in statistics, and her B.S. from the University of Science and Technology of China in math and applied math. She is currently working at Loyola Marymount University as an assistant professor. Her research interest is in bio mathematics modeling with simulations. 

Mathematics Colloquium (Jointly with Knots in Washington XL)

Speaker: Sergei Chmutov, Ohio State University, Mansfield
https://people.math.osu.edu/chmutov.1/

Title: In memory of Sergei Duzhin (1956–2015)
Date and Time: Tuesday,March 10, 2015

10:00–11:00am
Place: Duques Hall, Room 251

Abstract: I will recall life and work of my lifelong friend Sergei Duzhin who suddenly passed away on February 1, 2015. The main topic of my collaboration with Sergei Duzhin was Vassiliev knot invariants. Thus the mathematical part of my talk will concentrate on the theory of these invariants. I will first give definitions, survey the theory, and then explain our results and their further developments. I will then briefly talk about Duzhin’s life and some other of his results.

Short Bio: Sergei Chmutovis a professor of Mathematics at Ohio State University, Mansfield. He received his PhD from Moscow State University in 1985. His research interests include Vassiliev theory of knot invariants, knot theory, low-dimensional topology, theory of critical points of functions, combinatorics, (topological) graph theory, theory of singularities of algebraic varieties, and algebraic geometry. He authored 48 research papers and a book (jointly with S. Duzhin and Y. Mostovoy),Introduction to Vassiliev Knot Invariants, published by the Cambridge University Press in 2012.

Speaker: Gadi Fibich, Tel Aviv University, Israel

http://www.math.tau.ac.il/~fibich/

Title: Is heterogeneity important?

Date and Time: Friday, February 13, 2015, 1:00–2:00pm
Place: Government Hall, Room 101

Abstract: Typically, a model with a heterogeneous property is considerably harder to analyze than the corresponding homogeneous model. In this talk I will show that any outcome of a heterogeneous model that satisfies the two properties of differentiability and symmetry is O(ε2) equivalent to the outcome of the corresponding homogeneous model, where ε is the level of heterogeneity. In such cases, therefore, the effect of heterogeneity is minor. Applications of this “averaging principle’’ to problems in queuing theory, game theory (auctions), and marketing (diffusion of new products in social networks) will be presented.

Short Bio: Gadi Fibich got his PhD from NYU in 1994. He is a Professor of applied math at Tel Aviv University and is currently on sabbatical at the University of Maryland. He has numerous publications in various areas of applied math, including nonlinear optics, perturbations theory, applications to marketing, biochemistry, and medicine.

Title: Planar graphs are 9/2-colorable and have independence ratio at least 3/13
Speaker: Dan Cranston, Virginia Commonwealth University
Date and Time: Friday February 6, 1:00-2:00pm

Place: Government 101

Abstract: For nearly a century, one of the major open questions in graph theory was the Four Color Conjecture: Every planar graph can be properly colored with four colors. In 1976, this conjecture was resolved (in the affirmative) by Appel and Haken. Their result is called the 4 Color Theorem. Unfortunately, their proof (as well as later proofs of this theorem) relies heavily on computers. In contrast, the 5 Color Theorem is easy to prove. In this talk we look at a 9/2 Color Theorem, which we can prove by hand.

A 2-fold coloring assigns to each vertex 2 colors, such that adjacent vertices get disjoint sets of colors. We show that every planar graph G has a 2-fold 9-coloring. In particular, this implies that G has fractional chromatic number at most 9/2. This is the first proof (independent of the 4 Color Theorem) that there exists a constant k<5 such that every planar G has fractional chromatic number at most k. We also show that every n-vertex planar graph has an independent set of size at least 3n/13. This improves on Albertson's bound of 2n/9, which was the best result independent of the 4 Color Theorem.

This is joint work with Landon Rabern.

Short Bio: Daniel Cranston earned his PhD in 2007 from University of Illinois, under the direction of Douglas West. From September 2007 to August 2009, Cranston was a postdoctoral fellow at the Center for Discrete Mathematics and Theoretical Computer Science (DIMACS) and Bell Labs, Rutgers University and Murray Hill, NJ. Cranston is currently assistant professor in the Department of Mathematics and Applied Mathematics at Virginia Commonwealth University. His research interests are mainly in graph theory and algorithms, but he is also interested in most areas of discrete math. He has been awarded NSA Young Investigator’s Award for the next academic year.

Title: The continued fractions, Sturmian and Ostrowski numeration systems
Speaker: Abraham Bourla, American University
Date and Time: Friday, January 23, 1:00-2:00pm
Place: Government 101

Abstract: We will survey these three important non-fixed-radix numeration systems, each with a rich history and plenty of applications. We will present the built in connections between these systems and illustrate their geometric connections with the cutting sequences of geodesics and the rotation map on the circle.

Short Bio: Abraham Bourla worked as a computer programmer for the Israeli Defense Force and the private sector before coming to the US and studying mathematics. He has a Ph.D. from UConn and is currently teaching at AU.

Speaker: Rumen Dimitrov, Western Illinois University

Title: The Rich Structure of Modular Lattices Arising from Computably Enumerable Vector Spaces
Date and Time: January 16, 2015; 1:00–2:00 pm
Place: Monroe 250

Abstract:
Post’s problem in computability theory, dating back to 1944, is whether there exist a computably enumerable (c.e.) Turing degree that is neither computable nor the degree of the halting problem. His strategy was to find a non-computable co-infinite c.e. set with a “thin” complement. The original notion of thinness was called“simplicity.” A c.e. set the complement of which is infinite but has no infinite c.e. subset is called simple. Different, ever-stronger, notions of thinness were defined, but none of them gave a solution to Post’s problem. These notions, however, revealed some fascinating structural properties of the lattice E of c.e. sets under inclusion, and its factor lattice E* (E modulo finite sets). In the talk we will introduce the lattice L of c.e. subspaces of the fully algorithmic infinite dimensional vector space and its factor lattice L* (L modulo finite dimension). We will explore some important similarities and differences between E* and L*.

Time: Thursday, October 16, 2014, 3pm
Location: Phillips Hall 736
Speaker: David Kopriva (Florida State University)
Title: Spectral Methods in Motion

Abstract: Accurate computation of wave scattering from moving, perfectly reflecting objects, or embedded objects with materialproperties that differ from the surrounding medium, requires methods that accurately represent the boundary location and motion, propagate the scattered waves with low dissipation and dispersion errors, and don't introduce errors or artifacts from the movement of a mesh. Discontinuous Galerkin spectral element methods are especially suited to problems where wave propagation accuracy is needed and the locations of material discontinuities are known. Applying the methods to an ALE (Arbitrary Lagrangian-Eulerian) formulation extends them to moving boundary problems. In this talk, we discuss the issues and choices for the development of a DGSEM-ALE approximation for the accurate approximation of wave propagation problems with moving boundaries. Examples from acoustics, fluid dynamics and electromagnetics will be presented to illustrate the application of the methods.

Bio: David Kopriva is Professor of Mathematics at The Florida State University, where he has taught since 1985. He is an expert in the development, implementation and application of high order spectral multi-domain methods for time dependent problems. In 1986 he developed the first multi-domain spectral method for hyperbolic systems, which was applied to the Euler equations of gas dynamics. Though a multi-domain or spectral element approach is common now, at that time the idea of breaking up a computation into multiple spectral approximations was considered a radical idea. That original work led to the development of new multidimensional characteristic boundary conditions, spectral multi-domain methods for the compressible Navier-Stokes equations and multi-domain spectral versions of shock fitting algorithms for high speed flows. In the 1990's Kopriva developed a robust staggered grid Chebyshev spectral method that simplified the connectivity of subdomains and simplified parallel implementations. This work included the development of a non-conforming spectral method that enables the refinement of a mesh either by increasing the spectral order or decreasing the subdomain size locally. Most recently he has concentrated on the development of a discontinuous Galerkin form of the spectral element method for the solution of time-dependent systems. Kopriva has applied multi-domain spectral methods to time dependent problems in compressible flow, aeroacoustics and electromagnetics. Spectral multi-domain methods were used to solve problems in hypersonic flows over blunt bodies, in both the inviscid and viscous limits. Most recently he has applied the techniques he has developed to problems in electromagnetic scattering, problems in particulate transport, cryogenics and computational finance.

Speaker: Andrei Vesnin (Novosibirsk)
Title: Knot groups and discreteness conditions
Date and time: Friday, November 7, 1-2pm
Place: Duques 152

Abstract: There are various discreteness conditions for subgroups of PSL(2,C) acting on a hyperbolic 3-space. Most of conditions are related either to algebraic structure of a group or to its geometric action. It was shown by T. Jorgensen that a subgroup of PSL(2,C) is discrete if and only if any its 2-generated subgroup is discrete. Some of necessary conditions for 2-generated groups, obtained by T. Jorgensen, F. Gehring, G. Martin, and D. Tan, look as inequalities on traces of one generator and of a commutator of generators. We will say that a group is extreme if it gives the equality in such an inequality.

We will discuss hyperbolic knot groups and hyperbolic orbifold groups with are extreme groups for discreteness conditions (for example, the figure-eight knot and related orbifold groups). Also, we will discuss invariants of hyperbolic knots and links arising in this context.
 

Bio: Prof. Andrei Vesnin is head of the Laboratory of Applied Analysis, Sobolev Institute of Mathematics, Siberian Branch of Russian Academy of Sciences and a professor of Geometry and Topology, Novosibirsk State University. He received a Candidate of Sciences in physics and mathematics is 1991 from Sobolev Institute of Mathematics for the thesis ”Discrete groups of reflections and three-dimensional manifolds”, and a Doctor of Sciences in physics in mathematics in 2005 for the thesis ”Volumes and isometries of three-dimensional hyperbolic manifolds and orbifolds”. He was a visiting professor in Seoul National University in 2002 – 2004. Prof. Vesnin's reseach interests include low-dimensional topology, knot theory, hyperbolic geometry, combinatorial group theory, graph theory and applications.

He is the editor-in-chief of Siberian Electronic Mathematics Reports and a member of editorial boards of Siberian Mathematical Journal and Scientiae Mathematicae Japonicae. In 2008 Prof. Vesnin was elected to corresponding member of the Russian Academy of Sciences.

Special Colloquium Talk

Speaker: Uwe Kaiser (Boise State University)
Title: Topology from the Quantum Computation Viewpoint
Time: Tuesday, November 11, 11:10am -- 12:25pm (note the special time)
Location: Monroe 115

Abstract: The talk will give an elementary introduction into the models of classical respectively quantum computation as information processing by classical logic gates respectively quantum gates. Quantum information processing is distinguished by interference and entanglement in informationally isolated systems. These properties give rise to the well known "quantum weirdness". I will briefly discuss the mathematical description of quantum information processing (the axioms of quantum mechanics) by unitary operators acting on complex vector spaces. Some examples for the resulting apparent improvement in computational power of quantum over classical computation will be described. Quantum information processing systems involve the wave functions of composite system and the statistics of the particle exchange of identical particles. Understanding this particle exchange is been known for a long time to be related to the topology of particles moving in space. Interesting examples are so called anyons, quasi-particles moving in 2-space and known to appear e.g. in the fractional quantum Hall effect. Then quantum computation naturally asks to understand the mathematical model of anyons, which is a well-known subject in the field of quantum topology.

Bio: Dr. Uwe Kaiser received his PhD and habilitation from the University of Siegen in Germany. Additionally he also holds a K12-teaching certificate for Mathematics and Physics in Germany. Currently he is Associate Professor in the Mathematics Department at Boise State University, where he also serves as Associate Chair. His research interests are in Geometric and Algebraic Topology, more recently in Low Dimensional Topology and Quantum Topology, in particular in theory of skein modules. He is also working on several projects and grants related to STEM Education at Boise State University.

Speaker: Pavel Lushnikov (University of New Mexico)
Title: Finite time singularities, rogue waves and strong collapse turbulence
Date and time: Friday, November 21, 1-2pm.

Abstract: Many nonlinear systems of partial differential equations have a striking phenomenon of spontaneous formation of singularities in a finite time (blow up). Blow up is often accompanied by a dramatic contraction of the spatial extent of solution, which is called by collapse. Near singularity point there is a qualitative change in underlying nonlinear phenomena, reduced models loose their applicability and other mechanisms become important such as inelastic collisions in the Bose-Einstein condensate, optical breakdown and dissipation in nonlinear optical media and plasma, wave breaking in hydrodynamics. Collapses occur in numerous reduced physical and biological systems including a nonlinear Schrodinger quation (NLSE) and a Keller-Segel equation (KSE). We will focus on the collapse in the critical spatial dimension two (2D) which has numerous applications. For instance, 2D NLSE describes the propagation of the intense laser beam in nonlinear Kerr media (like usual glass) which results in the catastrophic self-focusing (collapse) eventually causing optical damage as was routinely observe in experiment since 1960-es. Recently such events have been also often referred as optical rogue waves. Another dramatic NLSE application is the formation of rogue waves in ocean. 2D KSE collapse describes the bacterial aggregation in Petri dish as well as the gravitational collapse of Brownian particles. We study the universal self-similar scaling near collapse, i.e. the spatial and temporal structures near blow up point. In the critical 2D case all these collapses share a strikingly common feature that the collapsing solutions have a form of either rescaled soliton (for NLSE) or rescaled stationary solution (for KSE). The time dependence of that scale determines the time-dependent collapse width L(t) and amplitude ~1/L(t). At leading order L(t)~ (t_c-t)^{1/2} for all mentioned equations, where t_c is the collapse time. Collapse
however requires the modification of that scaling which in NLSE has the well-known loglog type ~ (\ln|\ln(t_c-t)|)^{-1/2} as well as KSE has another well-known type of logarithmic scaling modification. Loglog scaling for NLSE was first obtained asymptotically in 1980-es and later proven in 2006. However, it remained a puzzle that this scaling was never clearly observed in simulations or experiment. Similar situation existed for KSE. Here solved that puzzle by developing a perturbation theory beyond the leading order logarithmic corrections for both NLSE and KSE. We found that the classical loglog modification NLSE requires double-exponentially large amplitudes of the solution ~10^10^100, which is unrealistic to achieve in either physical experiments or numerical simulations. In contrast, we found that our new theory is valid starting from quite moderate (about 3 fold) increase of the solution amplitude compare with the initial conditions. We obtained similar results for KSE. In both cases new scalings are in excellent agreement with simulations. This efficiency of analytical results also allowed to study 2D NLSE-type dissipative system in the conditions of multiple random spontaneous formation of collapses in space and time. Dissipation ensures collapse regularization while collapses are responsible for non-Gaussian tails in the probability density function of amplitude fluctuations which makes turbulence strong. Power law of non-Gaussian tails is obtained for strong NLSE turbulence which is a characteristic feature of rogue waves. We suggest the spontaneous formation optical rogue from turbulent as a perspective route to the combing of multiple laser beams, generated by a number of fiber lasers, into a single coherent powerful laser beam.

Short bio: Pavel Lushnikov received PhD in theoretical physics from the Landau Institute of Theoretical Physics. He moved to the postoctoral postion at the Los Alamos National Laboratory and later became the assistant professor at the University of Notre Dame. He joined UNM Department of Mathematics and Statistics in 2006 as the associate professor
and has been serving as the full professor since 2012. Since 2006 he has been awarded by 5 NSF and NSF/DOE grants. In 2008 he received Doctor of Science Degree in Physical and Mathematical Sciences, highest scientific degree in Russia, awarded for major scientific achievements beyond PhD by the Landau Institute. His interests include a wide range of topics in applied mathematics, nonlinear waves and theoretical physics. Among them are laser fusion and laser-plasma interaction; dynamics of fluids with free surface and nonlinear interactions of surface waves; theory of the wave collapse, singularity formation and its application to plasma physics, hydrodynamics, biology and nonlinear optics; high-bit-rate optical communication; dispersion-managed optical fiber systems; solution propagation in optical systems; high performance parallel simulations of optical fiber systems; Bose-Einstein condensation of ultracold dipolar gases. His recent Optics Letters paper on nonlinear beam combining, published in June 2014, has been in the top download of Optics Letters since then.
 

Speaker: Archana Khurana (University of Baltimore)
Date and time: Friday, December 5, 1-2pm.
Place: Duques 152

Title: On multi-index fixed charge bi-criterion transportation problem

Abstract:In this talk I would discuss an algorithm for solving a multi-index fixed charge bi-criterion transportation problem and also present a method for finding the optimum trade-off pair among the efficient cost-time trade-off pairs. The solution method would be useful when we need to transport heterogeneous commodities. The proposed algorithm minimizes variable and fixed costs simultaneously to yield an optimal basic feasible solution. I would also provide an algorithm to obtain an initial basic feasible solution of the multi-index transportation problem that may be used as a superior initial solution with any other existing procedure to enhance convergence to the optimal solution.

Bio:
Archana Khurana has obtained her Masters and Ph.D degree from Department of Mathematics, University of Delhi, Delhi, India. She was awarded Junior and Senior research fellowship from Council of Scientific and Industrial Research, Delhi, India during her Ph.D. After completion of her doctorate in 2004, she worked as a Research Engineer at Logistics Institute of Asia Pacific, National University of Singapore, Singapore for 1 year .

In September 2006, she joined Guru Gobind Singh Indraprastha University, Delhi, India and worked there till July 2013 where she taught undergraduate and graduate students. Thereafter she moved to USA and since August 2013, she is doing research at Merrick School of Business, University of Baltimore, Maryland, USA.

Her research interests are Linear and Non-linear programming, Transportation problems, Transshipment problems and Integer programming problems. Her thesis and ongoing research work has led to many publications in reputed International Journals. She was also sponsored a Major Research Project from University Grant Commission, Delhi, India of 3 years duration which was completed successfully. She loves travelling and playing Table tennis.

Spring 2014

Time: Friday, May 9, 2014 1:00-2:00
Place: GOV 102
Speaker: Neil J. A. Sloane, Mathematics Department, Rutgers University, Piscataway, NJ.

Abstract: The On-Line Encyclopedia of Integer Sequences is a database of number sequences, which in its fiftieth year now contains nearly a quarter of a million entries. This talk will describe some of the highlights, including the toothpick sequence, curling numbers, ``lunar'' arithmetic, and some very unusual recurrences. There will be several unsolved problems, music, and a movie.

Title: Diffusions, Fractional Laplacians and Traveling Waves
Speaker: Changfeng Gui, University of Connecticut and NSF
Time: Friday, March 21, 2014 1:00-2:00
Place: GOV 102

Abstract: Fractional Laplacians can be used to model physical phenomena involving abnormal diffusions. In this talk, I will discuss how abnormal diffusions may affect the propagation of certain materials/species. In particular, the effects of abnormal diffusions on the existence of traveling wave will be examined. For three important classes of diffusion-reaction models with monostable, combustion and bistable nonlinearities, we will show rigorous results for abnormal diffusions and compare them with the results for the classical models. The talk is based on recent results obtained jointly with Tingting Huan and with Mingfeng Zhao

Speaker: Michael Baake, University of Bielefeld, Germany
Time: Monday, March 31, 2014  2:45-3:45
Place: Monroe 267

The discovery of quasicrystals by Dan Shechtman in 1982 has shown that there are interesting systems beyond perfect crystals with pure point diffraction spectra, and also that we still have a rather limited understanding of what `order' is supposed to mean, both mathematically and physically.

In this talk, basic structures with aperiodic order are reviewed from the point of view of mathematical diffraction theory, with focus on classic and paradigmatic examples. The talk is directed towards a general mathematical audience. Further details will later be discussed in the talk by Uwe Grimm.

 Distinguished Speculative First of April Talk

Title: Topological, quantum and categorification invariants in 4D, unrealized opportunities
Speaker: Samuel J. Lomonaco Jr, (UMBC http://www.csee.umbc.edu/~lomonaco/),
Time: Thursday April 3, 2014 5:15pm
Place: Phil 108

Previous talks in the Distinguished Speculative First of April Talk series:
Title: I. Speculative, Distinguished First of April Talk
Speaker: Oleg Viro (Stony Brook University)
Time: Friday, April 1, 2011 3:45-4:45 pm
Place: Media & Public Affairs Building (21st & H), Room 310

II. Distinguished speculative April first talk
Title: The Four Color Theorem
Speaker: Louis Kauffman (University of Illinois at Chicago)
Time: Tuesday, April 3, 2012 4:00pm
Place: 1957 E Street, Room 111


III. Distinguished Speculative First of April Talk
Title: Quantum machine learning
Speaker: Seth Lloyd, MIT
Time: April 1, 2013,
http://www.rle.mit.edu/people/directory/seth-lloyd/
http://en.wikipedia.org/wiki/Seth_Lloyd

Speaker: Sarah Raynor is an associate professor of Mathematics at Wake Forest University in Winston-Salem, NC
Friday, February 21, 2014 1:00pm - 2:00pm

Room: Government 102

Title: Stability of Soliton Solutions to the Korteweg-deVries Equation

Abstract: In this talk, we introduce the Korteweg-deVries Equation, a canonical nonlinear differential equation modelling the behavior of surface water waves in a long, narrow, shallow canal. We study special solutions to this equation, known as solitons. We are particularly interested in the stability of these special solutions. Several concepts of stability will be introduced and explained.

Bio: Sarah Raynor is an associate professor of Mathematics at Wake Forest University in Winston-Salem, NC. After finishing her Ph.D. at MIT in 2003, she spent a year at the Fields Institute in Toronto before beginning her position at Wake Forest. Dr. Raynor is interested in partial differential equations, and particularly in dispersive equations, which model wave phenomena in mathematical physics.

Speaker: Juncheng Wei

Date and Time: Thursday, February 13, 2014; 2:20pm - 3:35pm

Place: Goverment #227

Title: Geomterization Program of Semilinear Elliptic PDEs

Abstract: Understanding the entire solutions of nonlinear elliptic equations in $R^N$ such as $Δu + f(u) = 0$ is a basic problem in PDE research. This is the context of various classical results in literature like the Gidas-Ni-Nirenberg theorems on radial symmetry, Liouville type theorems, or the achievements around De Giorgi’s conjecture. In those results, the geometry of level sets of the solutions turns out to be a posteriori very simple (planes or spheres). On the other hand, problems of this form do have solutions with more interesting patterns, and the structure of their solution sets has remained mostly a mystery. A major aspect of our research program is to bring ideas from Differential Geometry into the analysis and construction of entire solutions for two important equations: (1) the Allen-Cahn equation and (2) the nonlinear Schrodinger equation. Though simple-looking, they are typical representatives of two classes of semilinear elliptic problems. The structure of entire solutions is quite rich. In this talk, we shall establish an intricate correspondence between the study of entire solutions of some scalar equations and the theories of minimal surfaces and constant mean curvature surfaces (CMC).

Bio: Prof. Juncheng Wei at University of British Columbia is a Canada Research Chair in Partial Differential Equations. He is a prolific researcher who has written over 280 articles since 1995. His paper coauthored with M. Del Pino and M. Kowalczyk (Annals of Mathematics 174 (2011)) resolved the De Giorgi’s Conjecture in dimensions greater than 8. For this and other significant works, he is invited to give a lecture at 2014 International Congress of Mathematicians.

Title: Presentation about the Colonial One High Performance Cluster

Speaker:Glen MacLachlan from the CCAS Office of Technology Services
Friday, January 31, at 1-2pm

Place: # Gov 102

A presentation about the Colonial One High Performance Cluster next , our standard colloquium time. Colonial One has recently been procured by the GW and everyone working for CCAS can now get access to it in order to perform large-scale computations. You can read more about it here:
http://columbian.gwu.edu/ots/hpc

Glen's presentation will focus on how to start working with the Colonial One, which administrative and technical steps need to be completed, which types of queues exist, and so on. I've met with Glen today and he proposed to devote a portion of his time to a hands-on demonstration of the typical workflow involved in preparing and submitting cluster jobs.

Fall 2013

Speaker: Dr. Max Alekseyev  (University of South Carolina)
Date and Time: Monday, October 21, 2013 11:30am-12:30pm
Place: Monroe 267
Title: Challenges in Comparative Genomics: from Biological Problems to Combinatorial Algorithms (and back)

ABSTRACT: Recent large-scale sequencing projects fueled the comparative genomics studies and heightened the need for algorithms to extract valuable information about genetic and phylogenomic variations. Since the most dramatic genomic changes are caused by genome rearrangement events (which shuffle genomic material), it becomes extremely important to understand their mechanism and reconstruct the sequence of such events (evolutionary history) between genomes of interest. In this talk I shall describe several controversial and hotly debated topics in evolutionary biology (chromosome breakage models, mammalian phylogenomics, prediction of future rearrangements) and formulate related combinatorial challenges (rearrangement and breakpoint re-use analysis, ancestral genomes reconstruction problem). I shall further present my recent theoretic and algorithmic advances in addressing these challenges and their biological implications.

BIO: Dr. Max Alekseyev is an assistant professor at the Department of Computer Science and Engineering, University of South Carolina. He received a Ph.D. in computer science (2007) from the University of California, San Diego. In 2011, Dr. Alekseyev served as a scientific director for the Algorithmic Biology Laboratory at St. Petersburg Academic University, Russia, where he led development of genome assembler SPAdes. He received an NSF CAREER award in 2013. Dr. Alekseyev's research interests range from discrete mathematics (particularly, combinatorics and graph theory) to bioinformatics (particularly, comparative genomics and phylogenomics). His research is focused on the development and application of new methods of discrete mathematics to solve old and recently emerged open biological problems.

Speaker: Professor Anna Mazzuccato from Penn State

Date and Time: Friday, September 27, 2013 1pm

Place: Goverment #102

Title: Fluids flow at high Reynolds numbers Abstract: I will discuss how to model (incompressible) fluid flows at low viscosity or high Reynolds numbers. The Reynolds number measures the relative strength of convection with respect to dissipation. Such flows model turbulence phenomena. In particular, I will discuss whether enstrophy, the energy associated to vortices, is dissipated in the limit of vanishing viscosity in 2D flows. Enstrophy dissipation is a key aspect of the Kraichnan-Batchelor theory of turbulence. I will also discuss the zero-viscosity limit, that is, whether inviscid flows can approximate well viscous flows, in the presence of walls. No slip at rigid walls for viscous flows leads to the appearance of boundary layers. Layer separation and production of vorticity at walls is one of the most important mechanisms for forcing and mixing in flows.

Speaker: Jennifer Chubb (University of San Francisco)

Date and Time: Friday, September 20, 2013 1pm

Place: Government #102

Title: Quantum computing today

Abstract: The notion of quantum computing is not a very old one. It was Richard Feynman who, in 1981, first put forth the idea that computers designed to exploit the principles of quantum physics might have a leg up on classical computers. Since that time, loads of researchers have worked on

developing the theories of quantum computing, information, and cryptography, and many more are attempting to implement their discoveries. In this talk, we will survey the (brief) history of the subject, in addition to seeing something about what quantum computing is, and what makes quantum algorithms different from the programs we write every day for our classical machines.

Bio: Jennifer Chubb received her PhD in Mathematics from George Washington University in 2009 and is currently a member of the USF Math Department faculty. Her main research area is in mathematical logic specifically computability theory, and she has a particular interest in computable mathematical structures. Chubb also holds a BS in Physics & Applied Mathematics and an MS in Applied Mathematics from George Mason University. While pursuing those degrees, she worked in experimental physics and studied chaos and nonlinear dynamics. She is currently co-editing a volume on Logic and algebraic structures in quantum computing and quantum information.

Speaker: Dillon Mayhew, School of Mathematics, Statistics and Operations Research, Victoria University, Wellington, New Zealand.

Date and Time: Friday, September 13, 1pm

Place: Goverment #102

Title: Characterizing representable matroids

Abstract: Matroids abstract the notions of linear/geometric/algebraic dependence. More specifically, a matroid consists of a finite collection of points, and a distinguished family of dependent subsets. If we take a finite collection of vectors from a vector space, and distinguish the linearly dependent