| Date: | August 26, 2022 |
| Time: | 1:30pm |
| Location: | BLOC 628 |
| Speaker: | JM Landsberg, TAMU |
| Title: | Spaces of matrices of constant rank |
|
| Date: | September 2, 2022 |
| Time: | 1:30pm |
| Location: | BLOC 628 |
| Speaker: | Runshi Geng, TAMU |
| Title: | Intersections of unitary groups arising in quantum information theory |
|
| Date: | September 9, 2022 |
| Time: | 1:30pm |
| Location: | BLOC 628 |
| Speaker: | JM Landsberg, TAMU |
| Title: | Spaces of constant rank II: vector bundle perspective |
|
| Date: | September 16, 2022 |
| Time: | 1:30pm |
| Location: | BLOC 628 |
| Speaker: | Vincent Steffan, TAMU and Copenhagen |
| Title: | Quantum information theory news from Copenhagen |
|
| Date: | September 23, 2022 |
| Time: | 1:30pm |
| Location: | BLOC 628 |
| Speaker: | JM Landsberg, TAMU |
| Title: | Castelnuovo's lemma and Steiner bundles |
|
| Date: | October 7, 2022 |
| Time: | 1:30pm |
| Location: | BLOC 628 |
| Speaker: | Suhan Zhong, TAMU |
| Title: | Dehomogenization for Completely Positive Tensors |
| Abstract: | A real symmetric tensor is completely positive (CP) if it is a sum of symmetric tensor powers of nonnegative vectors. We propose a dehomogenization approach for studying CP tensors. This gives new Moment-SOS relaxations for CP tensors. Detection for CP tensors and the linear conic optimization with CP tensor cones can be solved more efficiently by the dehomogenization approach. |
|
| Date: | October 14, 2022 |
| Time: | 1:30pm |
| Location: | BLOC 628 |
| Speaker: | JM Landsberg, TAMU |
| Title: | Explicit spaces of constant rank via Steiner bundles |
|
| Date: | October 21, 2022 |
| Time: | 1:00pm |
| Location: | BLOC 628 |
| Speaker: | V. Steffan, TAMU/Copenhagen |
| Title: | Strassen's additivity conjecture and variants. |
|
| Date: | November 8, 2022 |
| Time: | 3:00pm |
| Location: | BLOC 302 |
| Speaker: | Xuehan Hu, TAMU |
| Title: | Small ball probabilities for simple random tensors |
| Abstract: | We study the small ball probability of simple random tensor X =
X(1) ⊗ · · · ⊗ X(l) where X(i), 1 ≤ i ≤ l are independent random vectors in
$\mathbb R^{n}$ that are log-concave or have density bounded by 1. We show that the
probability that the projection of X onto an m-dimensional subspace F falls
Within an Euclidean ball of length ε is upper bounded by Cεlog(1/\varepsilon)^{l−1} and ε
also this upper bound is sharp when m is small. When the subspace is spanned by orthonormal uniform random vectors on the unit sphere, then we can obtain a much better estimate with high probability in terms of the random subspace. |
|
| Date: | November 11, 2022 |
| Time: | 1:00pm |
| Location: | BLOC 628 |
| Speaker: | JM Landsberg, TAMU |
| Title: | A problem in graph theory and algebraic geometry |
| Abstract: | The problem: let K_s,t denote the complete bipartite graph with s edges on the left and t on the right. What is the largest number of edges in an n vertex graph not containing K_s,t as a subgraph? The use of algebraic geometry: a suitable random subvariety on the Segre P^b\times P^b over F_q furnishes the vertex set and the zero set of a random polynomial on the Segre furnishes the edges. This is work of Boris Bukh. In his proof he has to avoid a bad set which has interesting geometry that I'll discuss. |
|
| Date: | November 15, 2022 |
| Time: | 3:00pm |
| Location: | BLOC 302 |
| Speaker: | Xuehan Hu, TAMU |
| Title: | Survey on smoothed analysis of tensor decomposition |
| Abstract: | We introduce the smoothed analysis model of tensor decomposition and its applications in learning latent variable models. In particular, we are interested in the overcomplete case, that is, we are given a tensor in R^{n^l} with fixed rank r, where r>>n. We introduce Jennrich's Algorithm and discuss the conditions under which the algorithm will succeed with high probability. |
|
| Date: | November 18, 2022 |
| Time: | 1:00pm |
| Location: | BLOC 628 |
| Speaker: | H. Huang, Auburn |
| Title: | Hopf ring structures and spaces of symmetric tensors |
|
| Date: | December 2, 2022 |
| Time: | 1:00pm |
| Location: | BLOC 628 |
| Speaker: | Jan Draisma, U. Bern |
| Title: | A wonderful conjecture by Kazhdan and Ziegler |
| Abstract: | The conjecture: if f:Z ->{nxn-matrices over the complex numbers} is a c-quasihomomorphism (this
means that f(a+b)-f(a)-f(b) has rank at most c for all a,b in Z, then
f(a)-a*f(1) has rank at most some C=C(c), which doesn't depend on n.
I'll discuss the problem and Kazhdan-Ziegler's motivation, and our (Eggermont, Seynnaeve, Tairi, and I) solution in the diagonal case. |
|
Menu