## Seminars and Colloquia by Series

Series: Other Talks
Tuesday, November 27, 2018 - 13:05 , Location: Skiles Atrium , Cristobal Guzmanal Guzman , Universidad Católica de Chile, Chile , Organizer: Prasad Tetali
Cristobal Guzman will discuss his employment experience as an ACO alummus. The conversations will take place over coffee.
Series: Other Talks
Wednesday, November 14, 2018 - 04:00 , Location: Molecular Science and Engineering Building, Classroom G011 , Christopher Jarzynski , Director, Institute for Physical Science and Technology University of Maryland , Organizer: Rafael de la Llave
Thermodynamics provides a robust conceptual framework and set of laws that govern the exchange of energy and matter.  Although these laws were originally articulated for macroscopic objects, it is hard to deny that nanoscale systems, as well, often exhibit “thermodynamic-like” behavior.  To what extent can the venerable laws of thermodynamics be scaled down to apply to individual microscopic systems, and what new features emerge at the nanoscale?  I will review recent progress toward answering these questions, with a focus on the second law of thermodynamics. I will argue that the inequalities ordinarily used to express the second law can be replaced by stronger equalities, known as fluctuation relations, which relate equilibrium properties to far-from-equilibrium fluctuations.  The discovery and experimental validation of these relations has stimulated interest in the feedback control of small systems, the closely related Maxwell demon paradox, and the interpretation of the thermodynamic arrow of time.  These developments have led to new tools for the analysis of non-equilibrium experiments and simulations, and they have refined our understanding of irreversibility and the second law.   Bio Chris Jarzynski received an AB degree in physics from Princeton University in 1987, and a PhD in physics from the University of California, Berkeley in 1994. After postdoctoral positions at the University of Washington in Seattle and at Los Alamos National Laboratory in New Mexico, he became a staff member in the Theoretical Division at Los Alamos. In 2006, he moved to the University of Maryland, College Park, where he is now a Distinguished University Professor in the Department of Chemistry and Biochemistry, with joint appointments in the Institute for Physical Science and Technology and the Department of Physics. His research is primarily in the area of nonequilibrium statistical physics, where he has contributed to an understanding of how the laws of thermodynamics apply to nanoscale systems. He has been the recipient of a Fulbright Fellowship, the 2005 Sackler Prize in the Physical Sciences, and the 2019 Lars Onsager Prize in Theoretical Statistical Physics. He is a Fellow of the American Physical Society and the American Academy of Arts and Sciences.   Contact: Professor Jennifer Curtis                  Email: jennifer.curtis@physics.gatech.edu
Series: Other Talks
Tuesday, November 6, 2018 - 12:30 , Location: Skiles 006 , Dantong Zhu , Georgia Tech , , Organizer: Samantha Petti

This talk is organized by the Association for Women in Math (AWM). Everyone is welcome to attend.

In 1968, Mader showed that for every integer $p = 1, 2, …, 7$, agraph on $n \geq p$ vertices and at least $(p-2)n - \binom{p-1}{2} + 1$ edgeshas a $K_p$ minor. However, this result is false for $p = 8$ with the counter-example K2,2,2,2,2. In this talk, we will discuss this function presented byMader for $K_p$ where $p$ is bigger. We will also discuss related resultsproved using probabilistic methods and the relation of this problem toHadwiger’s conjecture.
Series: Other Talks
Tuesday, November 6, 2018 - 11:00 , Location: Howey N110 , Brian Swingle , Univ of Maryland , Organizer: Rafael de la Llave
I will discuss chaos in quantum many-body systems, specifically how it is relates to thermalization and how it fails in many-body localized states. I will conjecture a new universal form for the spreading of chaos in local systems, and discuss evidence for the conjecture from a variety of sources including new large-scale simulations of quantum dynamics of spin chains.
Series: Other Talks
Thursday, October 25, 2018 - 11:00 , Location: Skiles 006 , , Pompeu Fabra University, Barcelona , , 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 , , Pompeu Fabra University, Barcelona , , 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 , , 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 , , Pompeu Fabra University, Barcelona , , 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.&nbsp;

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 , , 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 , , 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.