String Theory Journal Club
2015/2016 | 2016/2017 | 2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024
2019-09-03 (Wtorek)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 15:00 
Mauricio Romo (Tsinghua University)SL(2,C) Chern-Simons and Volume Conjecture for Closed 3-manifolds
In this talk I will review the relation between the volumeconjecture (VC) for hyperbolic knot complements and its relation withSL(2,C) Chern-Simons (CS) theory. Afterwards I will move on to recentdevelopments connecting SL(2,C) CS to VC for closed hyperbolic3-manifolds that can be realized as Dehn filings of knot complements.This is mainly based on joint work with D. Gang and M. Yamazaki,arXiv: 1704.00918.
2019-07-09 (Wtorek)
Zapraszamy do sali 0.06, ul. Pasteura 5 o godzinie 12:00
Ben Webster (Perimeter Institute)Representation theory, topology and quantum field theory
There has been a lot of fruitful interaction in recent years between mathematics and quantum field theory, but also a lot of confusion on both sides. I'll try to explain how as a representation theorist with an occasional sidebar as a topologist, quantum field theory in low dimensions has proven useful for me, and how I hope to mathematics has some interesting things to say to quantum field theorists. In particular, 3 dimensional theories with N=4 supersymmetry prove to be a natural context for algebras which are non-commutative but almost commutative, such as universal enveloping algebras. There will be some results about relatively old areas like the representation theory of gl_n and newer ones like knot homology.
2019-06-17 (Poniedziałek)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 14:00
Paweł Ciosmak (MIMUW)From Vertex Algebras to Quantum Curves
In [1512.05785] Manabe and Sułkowski postulated and calculated in several cases the relation between Virasoro singular vectors and quantum cuvres for matrix models. This correspondence was afterwards investigated and confirmed from the point of view of conformal field theory [1712.07354v1]. The latter theory can be mathematically formalized via the notion of vertex algebras. In this talk I will introduce those algebras and show how to obtain quantum curves using them, making the approach of [1712.07354v1] more rigorous.
2019-05-29 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:00
Mauricio Romo (Tsinghua University)FJRW Theory and Hemisphere Partition Function
By using the hemisphere partition function for Gauged Linear Sigma Models as a guide, we obtain an expression for central charges of B-branes on LG orbifolds. This include exact expressions for the I-function and the Gamma class for a large class of LG orbifold theories. In mathematical terms, this is corresponds to an integral structure in Fan-Jarvis-Ruan-Witten (FJRW) theory. We extend some results from the mathematical literature and, if time allows, I will present some conjectures about flat coordinates in LG orbifolds. (A good review is https://arxiv.org/abs/1503.01223)
2019-05-22 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:00
Dmitry Noshchenko (IFT UW)Introduction to cluster algebras, part II: quivers, mutations and quantum dilogarithm
We continue discussing cluster algebras, this time diving into Faddeev's quantum dilogarithm and quiver mutations.
2019-05-15 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:00
Sibasish Banerjee (IFT UW)A tt* viewpoint of Landau-Ginzburg models in various dimensions
I will introduce the Landau-Ginzburg models in two dimensions and present the higher dimensional cases as their generalizations. Then, we will analyze the UV and IR limits through tt* viewpoint and we will contrast it with the Picard-Lefschetz theory in these contexts. Then finally we will comment on the connection of the tt* geometry and the associated Hitchin system for the 2d case.
2019-05-08 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:00
Dmitry Noshchenko (IFT UW)Cluster algebras and triangulations
In this talk I will give an introduction to cluster algebras associated to triangulations of surfaces, and discuss relations with quivers.
2019-04-17 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 13:00
Jakub Jankowski (IFT UW)Beginners view on resurgence
Perturbative expansions are ubiquitous in physics, often resulting in asymptotic series with zero radius of convergence. In order for the associated observables to become nonperturbatively well-defined one needs to use theory of resurgence. In this seminar I will give an incomers view on the theory of resurgence functions illustrating basic concepts with simplest examples. Some applications in physics will be shortly reviewed.
2019-04-03 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 12:30
Jakub Jankowski (IFT UW)Beginner's view on resurgence
Perturbative expansions are ubiquitous in physics, often resulting in asymptotic series with zero radius of convergence. In order for the associated observables to become nonperturbatively well-defined one needs to use theory of resurgence. In this seminar I will give an incomers view on the theory of resurgence functions illustrating basic concepts with simplest examples. Some applications in physics will be shortly reviewed. [W ramach seminarium NCBJ, sala NCBJ 207.]
2019-03-27 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:00
Piotr Kucharski (Caltech)Knots-quivers correspondence and A-polynomials
In this talk I will present how the physical interpretation of the knots-quivers correspondence allows us to introduce quiver A-polynomials and connect them to the usual A-polynomials defined for knots.
2019-03-18 (Poniedziałek)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 14:00
Dmitry Noshchenko (IFT UW)Introduction to Topological Recursion
In this talk an introduction to Topological Recursion (TR for short) will be presented. TR is a powerful mechanism to obtain an infinite tower of correlation functions, originated in matrix models. It has many applications, including various enumeration geometry problems and quantization. This talk will be focused on one particular model of counting graphs on Riemann surfaces of genus g, with n marked points.
2019-03-13 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:45
Vivek Singh (IFT UW)Multi-Boundary Entanglement within Chern-Simons theoretic framework
First, I will give a brief introduction to knot theory and its connection to Chern-Simons quantum field theory. Then, I will review recent developments on entanglement entropy (arXiv:1611.05460v2, arXiv:1611.01516v2, arXiv:1711.06474 & arXiv:1801.01131) associated with multi-boundary link complements. My plan is to highlight the interesting relationship between the volume of hyperbolic link complements to non-zero entanglement negativity and explore numerically the relevance from Borromean link computation.
2019-03-06 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:45
Carlos Perez Sanchez (IFT UW)On Non-Perturbative Tensor Field Theory
In this follow-up talk, I will expose some results in non-perturbative tensor field theory (i.e. random tensors in a quantum field theory framework). Concretely, the Ward-Identities and the Schwinger-Dyson equations will be derived.
2019-02-27 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:00
Carlos Perez Sanchez (IFT UW)Introducing Tensor Models
The interest in generalizing matrix models (seen as a random 2d-geometry framework) to higher dimensions led to tensor models, introduced by the end of last century. The interest in tensor models revived in the present decade, after their large-N expansion was found by Gurau. In this talk, I will introduce tensor models and focus in their geometrical and topological signification.
2019-02-04 (Poniedziałek)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:00
Sibasish Banerjee (IFT UW)Exponential networks in action and a tt* viewpoint, part II
We will start by a short recapitulation of Gaiotto-Moor-Neitzke's construction of spectral network for theories of class S. We will discuss the Cecotti-Vafa wall crossing in this context. Then we will move to the exponential networks. We will visit the example of framed C^3 (and if the time permits , some aspects of resolved conifold). We will finish by drawing connections with a higher dimensional (3d) tt* system.
2019-01-30 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 14:00
Sibasish Banerjee (IFT UW)Exponential networks in action and a tt* viewpoint, part I
We will start by a short recapitulation of Gaiotto-Moor-Neitzke's construction of spectral network for theories of class S. We will discuss the Cecotti-Vafa wall crossing in this context. Then we will move to the exponential networks. We will visit the example of framed C^3 (and if the time permits , some aspects of resolved conifold). We will finish by drawing connections with a higher dimensional (3d) tt* system.
2019-01-09 (Środa)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 11:15
Błażej Ruba (UJ)Topological Recursion and Airy Structures
Airy structures were introduced by Kontsevich and Soibelman as a new approach to topological recursion. It highlights the role of symplectic invariance and reinterprets the whole procedure as a special case of deformation quantization. I will review this idea and present its supersymmetric generalization.
2018-12-17 (Poniedziałek)
Zapraszamy do sali 5.42, ul. Pasteura 5 o godzinie 15:15
Sibasish Banerjee (MPI Bonn)Exploring 5d BPS spectra
We will develop geometric techniques for counting BPS states in five-dimensional gauge theories engineered by M theory on a toric Calabi-Yau threefold. The problem is approached by studying framed 3d-5d wall-crossing in presence of a single M5 brane wrapping a special Lagrangian submanifold L. The spectrum of 3d-5d BPS states is encoded by the geometry of the manifold of vacua of the 3d-5d system, which further coincides with the mirror curve describing moduli of the Lagrangian brane. The information about the BPS spectrum is extracted from the geometry of the mirror curve by construction of a nonabelianization map for the exponential networks. We will start by reviewing exponential networks, sketch the computation for a particular toric Calabi-Yau threefold. Finally, we will finish by remarking about several aspects of enumerative invariants for the Calabi-Yau threefolds.