Found 6 result(s)

### 14.10.2021 (Thursday)

#### Dynamical spin chains in 4D N = 2 SCFTs

Journal Club Elli Pomoni (DESY)

 at: 15:45 Otherroom Zoom, instructions in abstract abstract: In this talk we will revisit the study of spin chains capturing the spectral problem of 4d N = 2 SCFTs in the planar limit. At one loop and in the quantum plane limit, we will discover a quasi-Hopf symmetry algebra, defined by the R-matrix read off from the superpotential. This implies that when orbifolding the N = 4 symmetry algebra down to the N = 2 one and then marginaly deforming, the broken generators are not lost, but get upgraded to quantum generators. We will also demonstrate that these chains are dynamical, in the sense that their Hamiltonian depends on a parameter which is dynamically determined along the chain. At one loop we will show how to map the holomorphic SU(3) scalar sector to a dynamical 15-vertex model, which corresponds to an RSOS model, whose adjacency graph can be read off from the gauge theory quiver/brane tiling. One scalar SU(2) sub-sector is described by an alternating nearest-neighbour Hamiltonian, while another choice of SU(2) sub-sector leads to a dynamical dilute Temperley-Lieb model. These sectors have a common vacuum state, around which the magnon dispersion relations are naturally uniformised by elliptic functions. For the example of the â„¤_{2} quiver theory we study these dynamical chains by solving the one- and two-magnon problems with the coordinate Bethe ansatz approach. --- Part of the London Integrability Journal Club. If you are a new participant, please register at integrability-london.weebly.com. The link will be emailed on Tuesday.

### 04.11.2020 (Wednesday)

#### Type-B Anomalies on the Higgs Branch

Regular Seminar Elli Pomoni (DESY)

 at: 13:45 KCLroom Zoom, see abstract abstract: In this talk we will study type-B conformal anomalies associated with 1/2-BPS Coulomb-branch operators in 4D N=2 SCFTs. We will derive the conditions under which these anomalies can match across the conformal phase and the Higgs phase, and explicitly see them at work in concrete examples of both matching and non-matching. On the one hand matching leads to a new class of data on the Higgs branch of 4D N=2 SCFTs that are exactly computable. On the other, non-matching imposes novel restrictions on the holonomy of the conformal manifold. [For the Zoom link, please email to: alejandro.cabo_bizet@kcl.ac.uk ]

### 21.01.2020 (Tuesday)

#### TBA

Regular Seminar Elli Pomoni (DESY)

 at: 15:00 City U.room c309 abstract:

### 20.04.2017 (Thursday)

#### 2D CFT correlators for theories of class S_k

Regular Seminar Elli Pomoni (DESY)

 at: 14:00 QMWroom 610 abstract: We will introduce a large class of N=1 superconformal theories Sk which is obtained from Gaiottoâ€™s N=2 class S via orbifolding. We will study the Coulomb branch of the theories in the class by constructing and analyzing their spectral curves. Using our experience from the N=2 AGT correspondence we will search for a 2D/4D relations (AGTk) for the N=1 theories of class Sk. From the curves we will identify the 2D CFT symmetry algebra and its representations, namely the conformal blocks of the Virasoro/W-algebra, that underlie the 2D theory and reproduce the Seiberg-Witten curves of the N = 1 gauge theories. We find that the blocks corresponding to the SU(N) Sk gauge theories involve fields in certain non-unitary representations of the WkN algebra. These conformal blocks give a prediction for the instanton partition functions of the 4D N = 1 SCFTs of class Sk.

### 13.06.2012 (Wednesday)

#### M5-Branes, Toric Diagrams and Gauge Theory Duality

Regular Seminar Elli Pomoni (Humboldt U.)

 at: 14:00 ICroom H503 abstract:

### 16.11.2011 (Wednesday)

#### Spin Chains and Holography at the Veneziano limit

Triangular Seminar Elli Pomoni (Humboldt)

 at: 17:00 KCLroom K1.28 abstract: N = 2 SuperConformal QCD is perhaps the simplest theory outside the N = 4 "universality class" that we can attempt to study holographically. It is moreover continuously connected to the N = 4 class by an interpolating family of N = 2 SCFT. Careful analysis of its chiral spectrum points towards a gravity dual description via a non-critical string background. We then turn to the study of spin chains. The complete one-loop Hamiltonian and some higher-loop results already reveal a rich dynamics. We present past results and current progress.