NWU Set Theory Seminar (From 2024 January)
Hello~ Welcome to the Set Theory Seminar at Northwest Univeristy!🎉🎉🎉
This is a regularly held up seminar organized by graduates from 2014, Mathematics and Applied Mathematics at the School of Mathematics, Northwest University. We invite you to join us for discussions, presentations, and auditions.
For subscription, please send an email including your resume to any organizer below. For instance, you can send it to one of the organizer wanghm37@mail2.sysu.edu.cn. Once we have reviewed your resume, we will send you an email one day before, containing the title, abstract, and Tencent Meeting link for the upcoming event.
Our discussions typically take place on Fridays, once every one to two weeks. The inaugural session is scheduled for February 2, 2024, from 1:00 p.m. to 3:00 p.m (Beijing Time). You can find updated information on titles and abstracts on Seminar.
If you have any question or need help, feel free to ask!
News (Updated on 2025/06/16)
We are intended to organise an online seminar on Continuous Logic and Free Probability. Schedules and summaries are listed in 2025Special. Please feel free to joint us. Related information will be updated on this website.
Organizers
Cao Zilong (Mathematical Statistics)
PhD, School of Mathematics, Northwest University
Email: nwu_czl@stumail.nwu.edu.cn
Mu Miaomiao (Number Theory, Algebraic Geometry) *Female
PhD, School of Mathematical Sciences, University of Science and Technology of China
Email: mumm@mail.ustc.edu.cn
Qian Jingxu, (Mathematical Physics)
Graduate, Department of Physics, National University of Defense Technology
Email: qian_jingxu@alumni.nudt.edu.cn
Shao Kerun (Analysis, Partial Differential Equations)
Email: 12335003@zju.edu.cn
PhD, School of Mathematical Sciences, Zhejiang University
Sheng Xi (Analysis, Topology, Dynamic Systems)
PhD, School of Mathematical Sciences, University of Science and Technology of China
Email: sunx@mail.ustc.edu.cn
Wang Haoming (Combinatorics, Probability, Statistics)
PhD, School of Mathematics, Sun Yat-sen University
Email: wanghm37@mail2.sysu.edu.cn
Xue Xiaolong (Topology, Differential Geometry)
PhD, Department of Mathematical Sciences, Tsinghua University
Email: xxl19@mails.tsinghua.edu.cn
Yang Yixuan (Theoretical Computer Science, Mathematical Logic)
PhD, Department of Computer Science and Engineering, South University of Science and Technology of China & Department of Computer Science, Warwick University
Email: nakeryang@gmail.com
Upcoming Events
2025/11/15, 10:00 a.m., Tencent Meeting
Chen Zaoli (Cornell University)
Extreme Value Theory of Long-Range Dependent Sequences
In a long-range dependent setting, extreme values of a stationary processes exhibit both macroscopic and microscopic clustering features. Such an extremal clustering is subject to the dependence structure as well as the marginal distribution. In this talk, I will introduce the mechanism of a class of long-range dependent time series and its unique extremal behaviors. The talk is based on the following two articles.
[1] Extremal clustering under moderately long range dependence and moderately heavy tails, Z. Chen and G. Samorodnitsky, Stochastic Processes and Their Applications, 2022.
[2] Moderately Heavy Extreme Values under Extreme Long Range Dependence, Z. Chen, arXiv: 2505.23103.
2025/12/12, 10:00 a.m., Tencent Meeting
Tan Ju (Boston University)
Mirror Construction for Nakajima Quiver Varieties
In this paper, we construct the ADHM quiver representations and the corresponding sheaves as the mirror objects of formal deformations of the framed immersed Lagrangian sphere decorated with flat bundles. More generally, we construct Nakajima quiver varieties as localized mirrors of framed nodal unions of Lagrangian spheres in dimension two. This produces a mirror functor from the Fukaya category of a framed plumbing of surfaces to the dg category of complexes of bundles over the corresponding Nakajima quiver varieties.
For affine ADE quivers in specific multiplicities, the corresponding (unframed) Lagrangian immersions are homological tori, whose moduli of stable deformations are asymptotically locally Euclidean (ALE) spaces. We show that framed stable Lagrangian branes are transformed into monadic complexes of framed torsion-free sheaves over the ALE spaces.
A main ingredient is the notion of framed Lagrangian immersions and their Maurer-Cartan deformations. Moreover, using the formalism of quiver algebroid stacks, we find isomorphisms between the moduli of stable Lagrangian immersions and that of special Lagrangian fibers of an SYZ fibration in the affine \(A_n\) cases.
2025/12+, 10:00 a.m., Tencent Meeting
Shao Kerun (Zhejiang University)
Existence of global solutions to semilinear wave equations
TBA.
2025/12+, 10:00 a.m., TBA
Feng Yu (Tsinghua University)
TBA.
Past Events
2025/09/26, 10:00 a.m., Tencent Meeting
Lin Zhuowei (Nankai University, Center for Combinatorics)
The Combinatorics of Flagged Weyl Characters
In this talk, we introduce two aspects of flagged Weyl charcters, which can be restricted to Schubert polynomials. One is about coefficient-wise upper bounds and lower bounds of flagged Weyl charcters. This settles two conjectures proposed by Mészáros-St. Dizier-Tanjaya. The other one is about the principal specialization of Schubert polynomials, which improves the results previously obtained by Weigandt, Gao, and Mészáros-St. Dizier-Tanjaya.
Article1, Article2, and arXiv.
2025/07/04, 10:00 a.m., Tencent Meeting
Yang Zhilin (CAS)
Weak coupling limit of a Brownian particle in the curl of the 2D GFF
We study the weak coupling limit of the following equation in \(\mathbb{R}^2\): \[dX_t^\varepsilon=\frac{\hat{\lambda}}{\sqrt{\log\frac1\varepsilon}}\omega^\varepsilon(X_t^\varepsilon)dt+\nu dB_t,\quad X_0^\varepsilon=0. \] Here \(\omega^\varepsilon=\nabla^{\perp}\rho_\varepsilon*\xi\) with \(\xi\) representing the \(2d\) Gaussian Free Field (GFF) and \(\rho_\varepsilon\) denoting an appropriate identity. \(B_t\) denotes a two-dimensional standard Brownian motion, and \(\hat{\lambda},\;\nu>0\) are two given constants. We use the approach from to show that the second moment of \(X_t^\varepsilon\) under the annealed law converges to \((c(\nu,\hat\lambda)^2+2\nu^2)t\) with a precisely determined constant \(c(\nu,\hat\lambda)>0\), which implies a non-trivial limit of the drift terms as \(\varepsilon\) vanishes. We also prove that in this weak coupling regime, the sequence of solutions converges in distribution to \(\left(\sqrt{\frac{c(\nu,\hat\lambda)^2}{2}+\nu^2}\right)\widetilde{B}_t\) as \(\varepsilon\) vanishes, where \(\widetilde{B}_t\) is a two-dimensional standard Brownian motion.
2025/05/09, 10:00 a.m., Tencent Meeting
Xue Xiaolong (Tsinghua University)
The rigidity of eigenfunctions's gradient estimates
We introduce the rigidity results for eigenfunctions on Riemannian manifolds with nonnegative Ricci curvature. We also obtain the Li-Yau gradient estimate on convex domains and prove similar rigidity results.
Article in Mathematische Zeitschrift.
2025/02/26, 10:00 a.m., Tencent Meeting Password: ETDR
Yilong Zhang (Bonn University)
Green points in the reals
We construct an expansion of a real closed field by a multiplicative subgroup adapting Poizat's theory of green points Its theory is strongly dependent, and every open set definable in a model of this theory is semialgebraic. We prove that the real field with a dense family of logarithmic spirals, proposed by Zilber, satisfies our theory.