Found 10 result(s)

### 14.01.2020 (Tuesday)

#### ModulispacesofBPSWilsonloopsin3dandquivervarieties

 at: 13:30 ICroom H503 abstract: In this talk I will reexamine the classification of BPS Wilson loops in 3d super Chern-Simons-matter theories. Over the last several years a large class of increasingly intricate constructions of such operators have been found. They involve both discrete and continuous parameters chosen to satisfy varied conditions. In my talk I will explain that the discrete parameters are related to choosing a graded quiver diagram, which may be a subquiver or a cover of the one defining the theory. The continuous parameters are then a singular limit of the variety, a complex manifold, associated to that quiver.

### 24.01.2017 (Tuesday)

#### Matrixmodelsforthegauge-gravitycorrespondence

 at: 15:00 City U.room B103 abstract: The gauge-gravity correspondence identifies a field theory with a gravitational theory. The gravitational theory is weakly coupled when the field theory has large coupling and vice versa, which mostly prevents matching nontrivial results between the two descriptions. I will discuss cases when the field theory calculation can be reduced to a finite dimensional matrix integral, representing some counting problems. I will then evaluate the integral exactly and reexpand the exact result, which is valid for all coupling, at strong coupling. The resulting expression should match a weak coupling gravitational (or string theoretic) calculation and Iâ€™ll comment on what is known from that direction.

### 20.01.2016 (Wednesday)

#### PolygonSeminar:SUSYfieldtheoriesandmatrixmodels

 at: 15:00 ICroom LT3 Level 1 Blackett abstract: Matrix models are toy models for quantum field theories. They can be extremely complicated but can also be solved in a variety of ways. In my talk I will discuss general properties of matrix models and their solutions and focus on particular matrix models that arise in the study of 4d SUSY field theories. Those matrix models describe the index of the field theory, counting the number of states of the theory (with + sign for a boson and - for a fermion) and have been known for over 10 years. Though they look very complicated I will show how some simple tricks allow in certain cases to solve those matrix models exactly in terms of elementary functions. My talk will focus on the matrix model calculation and no specialized knowledge of SUSY field theories or indices would be required to follow it.

### 10.12.2014 (Wednesday)

 at: 14:00 ICroom H139 abstract: I will review the calculation of the partition function of 3d supersymmetric field theories on S^3 using the fermi-gas approach to solve the matrix integral. The resulting expression is an Airy function and is valid perturbatively to all orders in 1/N for a wide class of theories (including ABJM). This suggests that a similar formula can be derived by studying quantum gravity on AdS_4. I will explain several of the steps needed to implement this idea and some intriguing results.

### 22.02.2012 (Wednesday)

#### GeneralizedquarkantiquarkpotentialandtheTBTBA.

 at: 15:30 KCLroom Edmond J Safra Lecture Theatre abstract: Note: Sunil Mukhi's talk was cancelled!

### 20.10.2010 (Wednesday)

#### AsupermatrixmodelforABJMtheory

 at: 13:15 KCLroom 423 abstract: I will review the matrix model which calculates the partition function of ABJM theory on S3 as well as the expectation value of Wilson loop operators. I will then explain how this matrix model is solved and present the results for these quantities at all values of the couplings. At strong coupling these calculations reproduce the results of supergravity on Ads4 x CP3 and in particular the N to the 3/2 scaling of the free energy of the theory.

### 04.02.2010 (Thursday)

#### Asupermatrixmodelforsuper-Chern-Simons-Matter

 at: 12:00 ICroom Blackett 741 abstract: I will present the 1/2 BPS Wilson loop operator of N=6 super Chern- Simons-matter (ABJM theory) which is dual to the simplest macroscopic open string in AdS4 x CP3. The Wilson loop couples, in addition to the gauge and scalar fields of the theory, also to the fermions in the bi-fundamental representation of the U(N) x U(M) gauge group. These ingredients are naturally combined into a superconnection whose holonomy gives the Wilson loop, which can be defined for any representation of the supergroup U(NlM). Using the localization calculation of Kapustin et al. I will then show that the circular loop is computed by a supermatrix model and discuss the connection to pure Chern-Simons theory with supergroup U(NlM).