Seminars and Colloquia by Series

Series: Other Talks
Thursday, October 25, 2018 - 11:00 , Location: Skiles 006 , Lectures on Combinatorial Statistics , Pompeu Fabra University, Barcelona , gabor.lugosi@gmail.com , Organizer: Salvador Barone

Thanks are due to our colleague, Vladimir Koltchinskii, for arranging this visit. Please write to Vladimir if you would like to meet with Professor Gabor Lugosi during his visit, or for additional information.

In these lectures we discuss some statistical problems with an interesting combinatorial structure behind. We start by reviewing the "hidden clique" problem, a simple prototypical example with a surprisingly rich structure. We also discuss various "combinatorial" testing problems and their connections to high-dimensional random geometric graphs. Time permitting, we study the problem of estimating the mean of a random variable.
Series: Other Talks
Thursday, October 18, 2018 - 15:00 , Location: Skiles 006 , Lectures on Combinatorial Statistics , Pompeu Fabra University, Barcelona , gabor.lugosi@gmail.com , Organizer: Salvador Barone

Thanks are due to our colleague, Vladimir Koltchinskii, for arranging this visit. Please write to Vladimir if you would like to meet with Professor Gabor Lugosi during his visit, or for additional information.

In these lectures we discuss some statistical problems with an interesting combinatorial structure behind. We start by reviewing the "hidden clique" problem, a simple prototypical example with a surprisingly rich structure. We also discuss various "combinatorial" testing problems and their connections to high-dimensional random geometric graphs. Time permitting, we study the problem of estimating the mean of a random variable.
Series: Other Talks
Thursday, October 18, 2018 - 12:05 , Location: Skiles 006 , Boris Bukh , Carnegie Mellon University , Organizer: Lutz Warnke
What to do if the measurements that you took were corrupted by a malicious spy? We will see how the natural geometric approach to the problem leads to a geometry where lines are crooked, and triangles are square.
Series: Other Talks
Monday, October 15, 2018 - 12:00 , Location: Groseclose 402 , Lectures on Combinatorial Statistics , Pompeu Fabra University, Barcelona , gabor.lugosi@gmail.com , Organizer: Salvador Barone

Thanks are due to our colleague, Vladimir Koltchinskii, for arranging this visit. Please write to Vladimir if you would like to meet with Professor Gabor Lugosi during his visit, or for additional information. 

In these lectures we discuss some statistical problems with an interesting combinatorial structure behind. We start by reviewing the "hidden clique" problem, a simple prototypical example with a surprisingly rich structure. We also discuss various "combinatorial" testing problems and their connections to high-dimensional random geometric graphs. Time permitting, we study the problem of estimating the mean of a random variable.
Series: Other Talks
Thursday, September 13, 2018 - 11:05 , Location: Plaza along Atlantic Drive , Evans Harrell, Kristel Tedesco, Chaowen Ting, musicians, and performers , Georgia Tech , harrell@math.gatech.edu , Organizer:
This is an interdisciplinary event using puzzles, story-telling, and original music and dance to interpret Euler's analysis of the problem of the Seven Bridges of Königsberg, and the birth of graph theory.  Beginning at 11:00, students from GT's Club Math will be on the plaza between the Howie and Mason Buildings along Atlantic Dr., with information and hands-on puzzles related to Euler and to graphs.  At 12:00 the performance will begin, as the GT Symphony Orchestra and a team of dancers interpret the story of the Seven Bridges.  For more information see the news article at http://hg.gatech.edu/node/610095.
Series: Other Talks
Thursday, September 6, 2018 - 10:00 , Location: Skiles 006 , Forrest Kieffer , Georgia Tech , tkieffer3@gatech.edu , Organizer: Forrest Kieffer
The three-dimensional Maxwell-Pauli-Coulomb (MPC) equations are a system of nonlinear, coupled partial differential equations describing the time evolution of a single electron interacting with its self-generated electromagnetic field and a static (infinitly heavy) nucleus of atomic number Z. The time local (and, hence, global) well-posedness of the MPC equations for any initial data is an open problem, even when Z = 0. In this talk we present some progress towards understanding the well-posedness of the MPC equations and, in particular, how the existence of solutions depends on the stability of the one-electron atom. Our main result is that time global finite-energy weak solutions to the MPC equations exist provided Z is less than a critical charge.  This is an oral comprehensive exam. All are welcome to attend.
Series: Other Talks
Tuesday, August 14, 2018 - 14:00 , Location: Skiles 154 , Justin Lanier , Georgia Tech , jlanier8@gatech.edu , Organizer: Justin Lanier
Take a branched covering map of the sphere over itself so that the forward orbit of each critical point is finite. Such maps are called Thurston maps. Examples include polynomials with well-chosen coefficients acting on the complex plane, as well as twists of these by mapping classes. Two basic problems are classifying Thurston maps up to equivalence and finding the equivalence class of a Thurston map that has been twisted. We will discuss ongoing joint work with Belk, Margalit, and Winarski that provides a new, combinatorial approach to the twisted polynomial problem. We will also propose several new research directions regarding Thurston maps. This is an oral comprehensive exam. All are welcome to attend.
Series: Other Talks
Tuesday, April 10, 2018 - 11:00 , Location: Skiles 006 , Prof. Oded Margalit , CTO, IBM Cyber security center of excellence at Ben Gurion, University of the Negev , Organizer: Prasad Tetali

[CV: Prof. Oded Margalit, PhD in Computer Science from Tel-Aviv University under the
supervision of Prof. Zvi Galil has worked at IBM's Haifa research lab on
machine learning, constraint satisfaction, verification and more. Currently he is the CTO
of the IBM Cyber security center of excellence at Ben Gurion University
of the Negev. Oded participates in organising several computer science
competitions (like the international IEEEXtreme and the national CodeGuru). He loves riddles and authors the monthly
challenge corner of IBM research: "Ponder-This".]

IBM research runs a mathematical challenge site. Every month a new challenge is posted; as well as a solution for the previous month's riddle. Prof. Oded Margalit is the puzzlemaster, for the last decade.  In the talk, he will survey some of the riddles over the years, and tell some anecdotes about the challenges and the solvers. For example: A PRL paper born from a riddle on random walks; ITA-2014 paper on water hose model (using quantum entanglement to break location based encryption); Games: 2048, Kakuro, Infinite chess game, the probability of a backgammon to end with a double, Fisher Foul Chess and more. Minimal hash function, Combinatorial Test Design; A solver from Intensive Care Unit and other stories; Finding a natural number n such that round ((1+2 cos(20))^n) is divisible by 10^9; We'll leave you with a still open question about Permutation-firing cannon...  Don't worry - no high math knowledge is assumed.
Series: Other Talks
Sunday, March 11, 2018 - 16:00 , Location: Drew Charter School , various performers , GT, Emory, Little Minute , Organizer:
This is an Atlanta Science Festival performance in which mathematicians team up with dancers to give an artistic interpretation to the public of some mathematicians and some mathematical concepts.  This year's show will have an emphasis on graph theory.  There will be two performances at Drew Charter School in East Atlanta.  For tickets go to https://www.freshtix.com/events/mathematics-in-motion---4pm-showing or https://www.freshtix.com/events/mathematics-in-motion---7pm-showing .
Series: Other Talks
Friday, February 23, 2018 - 17:00 , Location: Classroom 105 in the D.M. Smith building , Associate Professor , Swarthmore College , Organizer: Joseph Rabinoff
Degeneracy loci of morphisms between vector bundles have been used in a wide range of situations, including classical approaches to the Brill--Noether theory of special divisors on curves. I will describe recent developments in Schubert calculus, including K-theoretic formulas for degeneracy loci and their applications to K-classes of Brill--Noether loci. These recover the formulas of Eisenbud--Harris, Pirola, and Chan--López--Pflueger--Teixidor for Brill--Noether curves. This is joint work with Dave Anderson and Nicola Tarasca.

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