Seminar on QFT and Geometry

Speaker:Hao Wang
Organizer:Hao Wang, Xiaoyue Sun
Time:2024/1/19(Friday);15:00-17:00pm
Venue:静斋304 (Jingzhai 304)

Upcoming talk:

 

Title: BPS state and spectral network(II)

Speaker:Hao Wang

Time: 2024/1/19(Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)

 

Abstract:

We will start from some basic supersymmetric quantum field theory to introduce how the concept of BPS states emerges in SUSY gauge theory, then I will talk about a simple example of wall-crossing phenomena and its conctext in 4d N=2 theory. The lecture is based on the lecture notes of Andrew Neitzke"Lectures on BPS states and spectral networks". 

 



Past talks: 


Title: Continuing some basics of 3d SUSY and Gauge Theory

Speaker: Myungbo Shim

Time: 2024/1/12(Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)


Abstract:

We will continue the previous discussion about the 3d gauge theory and explore important features of gauge theories in supersymmetric set-up under the guidance od Intrilligator and Seiberg 




Title: BPS state and spectral network(I) 

Speaker: Hao Wang (YMSC)

Time: 2023/12/22(Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)

 

Abstract:

We will start from some basic supersymmetric quantum mechanics and its properties, then we will introduce some basic notions of supersymmetry algebra and its representation in the context of 1d/2d N=2 supersymmetry.In the end, I will talk about some richer examples. The lecture is based on the lecture notes of Andrew Neitzke"Lectures on BPS states and spectral networks".




Title: Network and Seiberg duality(III)  

Speaker Hao Wang (YMSC)

Time: 2023/12/15 (Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)


Abstract:

This time we will discuss the 4d N=1 Seiberg duality emerged from the bordered Riemann surface construction. Specifically, we will consider how the open pants decomposition and ideal triangulaiton are involved in the construction. In the end we will talk about some general properties of these theories. 



 

Title: Network and Seiberg duality (II) 

Speaker: Hao Wang (YMSC)

Time: 2023/12/08(Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)

Abstract:

This time I will introduce a classification of 4d N=1 superconformal quiver gauge theory associated with a planar bipartitie network we talked about in partI using permutation, I will talk about the relation between the permutation an network. Then I will talk about its relation with the totally nonnegative Grassmannian, if time allowed, we can go to the case of 4d N=1 theory associated to a bordered Riemann surface.




Title: Some basics of 3d SUSY gauge theories

Speaker: Myungbo Shim (YMSC)

Time: 2023/12/01(Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)

Abstract:

We are going to have a tour in 3d gauge theories with and without supersymmetry. First of all, we will look at special features of 3d gauge theories: topological symmetry, monopole operator, and coupling to background gauge fields, particle-vortex duality and SL(2,Z) duality action. After that, we briefly look at some basic ingredients of N=2 supersymmetry, and explore the results of Aharony-Hanany-Intriligator-Seiberg-Strassler and Intriligator-Seiberg on N=2 SUSY gauge theory with and without Chern-Simons term. If time allows, finally we will see what is actually going on the SUSY localization in 3d very briefly. 




Title: Network and Seiberg duality(I)

Speaker Hao Wang (YMSC)  

Time: 2023/11/24 (Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)


This time I will introduce a class of 4d N=1 superconformal quiver gauge theory associated with a planar bipartitie network defined by Dan Xie and Masahito Yamazaki, the IR fixed points of several UV description can be classified by a cell of totally non-negative Grassmannian.




Title: 3-manifolds and 3d indices(V)  

Speaker: Hao Wang (YMSC)

Time: 2023/11/10 (Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)


This time I will use the bipyramid theory as an example to show how to glue the tetrahedron theory into a single theory. The bipyramid theory is a very important example which essentiallyt the 3d N=2 mirror symmetry of SQED and XYZ model, corresponding to the 2-3 moves of the bipyramid geometry.




Title: 3-manifolds and 3d indices(IV) 

Speaker: Hao Wang (YMSC)

Time: 2023/11/03 (Friday);15:00-17:00 pm

Venue:静斋304 (Jingzhai 304)


This time I will continue to talk about the basic knowledge of 3-manifold we need to construct the 3d index last time. Then due to the content adjustment, I will introduce the tetrahedron index this time which was planned for last time and the properties of tetrahedron index, then by using the gluing rule and ideal triangulation, we will go to the 3d index for general 3-manifold theory.



 

Title: 3-manifolds and 3d indices(III)  

Speaker: Hao Wang (YMSC)

Time: 2023/10/27 (Friday);15:00-17:00 pm

Venue:静斋304 (Jingzhai 304)


I will introduce the basic operator algebra we will use to construct the quantum Lagrangian operators later, then starting from the tetrahedron index, one can use the gluing rule to construct the 3d index for general 3-manifolds which admit ideal triangulations. If time permits, I will give calculation examples on bipyramid and trefoil complement.



 


Title: 3-manifolds and 3d indices(II) 

Speaker:Hao Wang (YMSC)

Time: 2023/10/13 (Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)


This time I will continue to talk about the Dimofte-Gaiotto-Gukov construction on the class R of 3d N=2 SCFT. Last time we introduced the basic concepts of the tetrahedron index and its properties. This time I will talk about how to construct the 3d index for general 3-manifold out of the tetrahedron index. The reference of this talk is 1112.5179. 




Title: 3-manifolds and 3d indices(I) 

Speaker:Hao Wang (YMSC)

Time:2023/09/22 (Friday);15:00-17:00pm

Venue:静斋304 (Jingzhai 304)


This time I will talk about the Dimofte-Gaiotto-Gukov construction on the class R of 3d N=2 superconformal field theory, which includes the effective theories T_M of M5-branes wrapped on 3-manifold M and more generally includes the theories that admit the UV description as abelian Chern-Simons-matter theory. I will introduce the concept of tetrahedron index and use it to construct the superconformal index of the theories in class R. The reference of this talk is 1112.5179.