Seminars and Colloquia by Series

Scaling down the laws of thermodynamics

Series
Other Talks
Time
Wednesday, November 14, 2018 - 04:00 for 1 hour (actually 50 minutes)
Location
Molecular Science and Engineering Building, Classroom G011
Speaker
Christopher JarzynskiDirector, Institute for Physical Science and Technology University of Maryland
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

The extremal function for $K_p$ minors

Series
Other Talks
Time
Tuesday, November 6, 2018 - 12:30 for 30 minutes
Location
Skiles 006
Speaker
Dantong ZhuGeorgia Tech

Please Note: 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.

Quantum Chaos, Thermalization, and Localization

Series
Other Talks
Time
Tuesday, November 6, 2018 - 11:00 for 1 hour (actually 50 minutes)
Location
Howey N110
Speaker
Brian SwingleUniv of Maryland
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.

Gabor Lugosi lectures on combinatorial statistics (3 of 3)

Series
Other Talks
Time
Thursday, October 25, 2018 - 11:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Lectures on Combinatorial StatisticsPompeu Fabra University, Barcelona

Please Note: 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.

Gabor Lugosi lectures on combinatorial statistics (2 of 3)

Series
Other Talks
Time
Thursday, October 18, 2018 - 15:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Lectures on Combinatorial StatisticsPompeu Fabra University, Barcelona

Please Note: 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.

Undergraduate Seminar (extra thursday lecture): When triangles turn square

Series
Other Talks
Time
Thursday, October 18, 2018 - 12:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Boris BukhCarnegie Mellon University
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.

Gabor Lugosi lectures on combinatorial statistics (1 of 3)

Series
Other Talks
Time
Monday, October 15, 2018 - 12:00 for 1 hour (actually 50 minutes)
Location
Groseclose 402
Speaker
Lectures on Combinatorial StatisticsPompeu Fabra University, Barcelona

Please Note: 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.

The Seven Bridges of Königsberg

Series
Other Talks
Time
Thursday, September 13, 2018 - 11:05 for 2 hours
Location
Plaza along Atlantic Drive
Speaker
Evans Harrell, Kristel Tedesco, Chaowen Ting, musicians, and performers Georgia Tech
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.

Global Finite-Energy Solutions to the Maxwell-Pauli-Coulomb Equations

Series
Other Talks
Time
Thursday, September 6, 2018 - 10:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Forrest KiefferGeorgia Tech
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.

Twisting polynomials: new directions in the study of Thurston maps

Series
Other Talks
Time
Tuesday, August 14, 2018 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 154
Speaker
Justin LanierGeorgia Tech
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.

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