Department of Mathematics,
University of California San Diego
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Advancement to Candidacy
Yuqian Zhang
UCSD
High-dimensional Semi-supervised Inference: Mean and Variance Estimation
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SDSC RM 408
SDSC RM 408
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Department of Mathematics,
University of California San Diego
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Math 295 - Mathematics Colloquium
Brandon Seward
NYU
Bernoulli shifts and entropy theory
Abstract:
In ergodic theory, one often studies measure-preserving actions of countable groups on probability spaces. Bernoulli shifts are a class of such actions that are particularly simple to define, but despite several decades of study some elementary questions about them still remain open, such as how they are classified up to isomorphism. Progress in understanding Bernoulli shifts has historically gone hand-in-hand with the development of a tool known as entropy. In this talk, I will review classical concepts and results, which apply in the case where the acting group is amenable, and then I will discuss recent developments that are beginning to illuminate the case of non-amenable groups.
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AP&M 6402
AP&M 6402
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Department of Mathematics,
University of California San Diego
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Food For Thought Seminar
Shubham Sinha
UCSD
Journey to the core of partitions!
Abstract:
Integer partitions have been an interesting combinatorial object for centuries but we still have a lot left to understand. In this talk we will see an uncommon way to view partitions using 'Abaci' and use this to illustrate partition division (defining t-cores and t-quotients of a given integer partition). I am planning to go in more detail with a special kind of partition called t-core partitions and discuss different ways to enumerate them. I will end my talk by stating an interesting results by Prof. Ken Ono, which shows how the related objects enumerates some important algebraic invariants like class groups of certain imaginary quadratic number fields.
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AP&M 7321
AP&M 7321
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Department of Mathematics,
University of California San Diego
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Math 258 - Differential Geometry
Teng Fei
Columbia University
Hull-Strominger system and Anomaly flow over Riemann surfaces
Abstract:
The Hull-Strominger system is a system of nonlinear PDEs describing the geometry of compactification of heterotic strings with torsion to 4d Minkowski spacetime, which can be regarded as a generalization of Ricci-flat K$\ddot{\text{a}}$hler metrics coupled with Hermitian Yang-Mills equation on non-K$\ddot{\text{a}}$hler Calabi-Yau 3-folds. The Anomaly flow is a parabolic approach to understand the Hull-Strominger system initiated by Phong-Picard-Zhang. We show that in the setting of generalized Calabi-Gray manifolds, the Hull-Strominger system and the Anomaly flow reduce to interesting elliptic and parabolic equations on Riemann surfaces. By solving these equations, we obtain solutions to the Hull-Strominger system on a class of compact non-K$\ddot{\text{a}}$hler Calabi-Yau 3-folds with infinitely many topological types and sets of Hodge numbers. This talk is based on joint work with Zhijie Huang and Sebastien Picard.
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AP&M 6402
AP&M 6402
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