Please feel free to contact any one of us, if you would like to give a talk at our seminar.
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Date Time |
Location | Speaker |
Title – click for abstract |
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01/16 3:00pm |
BLOC 628 |
Liyuan Chen Harvard University |
Universal Circuit Set using the S3 Quantum Double
Topological quantum computation with non-Abelian anyons offers a promising path toward fault-tolerant universal quantum computation. However, the practical realization of such a system remains challenging due to the difficulty of finding suitable topological materials. In this work, we provide a comprehensive blueprint for constructing a large-scale quantum computer based on the quantum double model $\mathcal{D}(S_3)$, a specific non-Abelian topological order. We implement logical computations using quantum circuits on qubits and qutrits, including a single non-Clifford gate, compatible with near-term quantum devices. This work bridges the gap between abstract mathematical frameworks and noise-resilient quantum computation on near-term devices. Our proposal offers a promising path to realize an anyon-based quantum computer. |
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03/21 4:00pm |
BLOC 302 |
Demetre Kazaras Michigan State University |
Scalar curvature and codimension 2 collapse
This talk is about the structure of Riemannian 3-manifolds satisfying a lower bound on their scalar curvature. These manifolds are models for spatial geometry in general relativity. Our motivational question will be "How flat is an isolated gravitational system with very little total mass?" Objects like gravity wells and black holes can distort geometry without accumulating much mass, making this a subtle question. In addition to discussing progress, I will present a "drawstring" construction, which modifies a manifold near a given curve, reducing its length with negligible damage to a scalar curvature lower bound. Unexpected examples are produced with relevance to a few problems. This construction extends ideas of Basilio-Dodziuk-Sormani and Lee-Naber-Neumayer, and is based on joint work with Kai Xu. |
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03/25 4:00pm |
BLOC 605AX |
Gennadi Kasparov Vanderbilt University |
Index theory on manifolds with a tangent Lie srtructure
In recent years there was a significant progress in the theory of pseudo-differential operators on filtered manifolds. In my talk I will introduce a wider class of manifolds which I call manifolds with a tangent Lie structure. I will explain a coarse approach to pseudo-differential theory which gives a simplified pseudo-differential calculus containing only operators of order 0 and negative order. This calculus easily leads to the Atiyah-Singer type index theorem for operators of order 0 on manifolds with a tangent Lie structure. For filtered manifolds this calculus agrees with the known Hormander and van Erp - Yuncken calculi, which allows to extend the index theorem to operators of any order. |
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03/26 2:00pm |
BLOC 302 |
Xuan Yao Cornell University |
On the topology of manifolds with positive intermediate curvature
We formulate a conjecture relating the topology of a manifold's universal cover with the existence of metrics with positive $m$-intermediate curvature. We prove the result for manifolds of dimension $n\in\{3,4,5\}$ and for most choices of $m$ when $n=6$. As a corollary, we show that a closed, aspherical 6-manifold cannot admit a metric with positive $4$-intermediate curvature.
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03/26 4:00pm |
BLOC 628 |
Thorsten Hertl University of Melbourne |
Moduli Spaces of Positive Curvature Metrics
In the last decade the observer moduli space of Riemannian metrics with positive curvature conditions have become more and more popular. So far, results in this direction only work if the dimension of the underlying manifold is bigger than 5 or if the manifold is spin. I will present a different construction that works in dimension 4 and does not rely on spin geometry. |
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04/02 2:00pm |
BLOC 302 |
Jun Yang Harvard University |
The Atiyah-Schmid formula for Jacquet-Langlands correspondence
We extend the Atiyah-Schmid formula from semi-simple groups to reductive groups. Based on the extended formula, we show that the dimension over arithmetic groups is an invariant under the Jacquet-Langlands correspondence. |
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04/09 2:00pm |
BLOC 302 |
Jintao Deng University at Buffalo |
The fibred coarse embedding and the coarse Novikov conjecture
The coarse Novikov conjecture claims that a certain assembly map from the K-homology of a metric space to the K-theory of its Roe algebra is injective. It was verified for a large class of metric spaces including the space admitting a fibred coarse embedding into Hilbert space. In this talk, I will talk about the notion of fibred coarse embedding introduced by X. Chen, Q. Wang and G. Yu, and its generalization, so called FCE-by-FCE structure. I will also talk about the coarse Novikov conjecture for a space with an FCE-by-FCE structure. This is based a joint work with L. Guo, Q. Wang and G. Yu. |
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04/16 2:00pm |
BLOC 302 |
Lara Ismert University of Nebraska-Lincoln |
The infinite path space of a quantum graph
In a 2022 article, Brannan, Eifler, Voigt, and Weber defined an equivalent notion of a quantum graph via a {\em quantum adjacency matrix} on a finite-dimensional {\em quantum set}. As a quantum analogue of a Schur idempotent matrix, a quantum graph’s quantum adjacency matrix serves as a jumping off point to generalize the Cuntz—Krieger algebra arising from a classical {0,1}-matrix. The four authors also introduced two quantum Cuntz—Krieger relations on a non-commutative finite-dimensional C*-algebra which generalize the respective Cuntz—Krieger relations defined on a commutative finite-dimensional C*-algebra. |
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04/23 2:00pm |
BLOC 302 |
Siqing Zhang Institute for Advanced Study |
Hodge Theory Multiverse
In this talk, I will give a gentle overview of various incarnations of the Hodge Theory: abelian and nonabelian, complex, p-adic and mod p. I will then explain some recent advances in the mod p nonabelian setting, emphasizing how they fit into the grand picture. I try to make this talk accessible to all kinds of geometers.
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