# Journalklubb

Målgruppen för journalklubben är doktorander och postdocs som forskar om olika ämnen inom teoretisk fysik. Idén är att vi möts för att lära oss och diskutera klassiska och intressanta ämnen inom teoretisk fysik.
Organisatör: Matthew Magill (matthew.magill@physics.uu.se)

## Talks - Spring 2021

Exact properties of an integrated correlator in N=4 SU(N) SYM

Speaker: Carlos Gustavo Rodriguez Fernandez
Papers:

• Exact properties of an integrated correlator in N=4 SU(N) SYM 2102.09537

Date: 09 April 2021, 1.30 - 3.00 pm
Location: Zoom

Exact solutions in N=2 D=4 Gauged Supergravity coupled to abelian vector multiplets

Speaker: Davide Astesiano
Papers:

• Super throats with non trivial scalars 2003.11582
• De Sitter magnetic black hole dipole with a supersymmetric horizon 2012.04362

Date: 19 March 2021, 1.30 - 3.00 pm
Location: Zoom

Classical de Sitter solutions between two mirrors: A new recipe?

Speaker: Daniel Panizo Pérez
Abstract: In this talk, we will take a look at new results from type IIA supergravity compactifications. A four-dimensional space with positive cosmological constant is obtained by solving the ten-dimensional equations of motion. To achieve these results, a characteristic topology and O-planes are required. However, this achievement is not free of controversy, as some of its features are not well-understood or are incompatible with no-go theorems. We will introduce all required ingredients that are present in these results and then examine their properties.
Papers:

• Classical de Sitter Solutions of Ten-Dimensional Supergravity 1812.04147
• No classical (anti-)de Sitter solutions with O8-planes 1902.08209
• New de Sitter Solutions in Ten Dimensions and Orientifold Singularities 1911.04498
• What if string theory has no de Sitter vacua? 1804.01120
• Smeared versus localised sources in flux compactifications 1009.1877
• Daniel's notes

Date: 05 March 2021, 1.30 - 3.00 pm
Location: Zoom

3D Chern-Simons theory and the R matrix

Speaker: Maor Ben-Shahar
Abstract: I will explain the details of the construction of a classical r-matrix from 3D Chern-Simons theory following [1905.03263]. The construction relies on imposing unconventional gauge choices and boundary conditions on $R^2 \times I$. These choices imply that expectation valued of knots are always well-defined (no framing anomaly), but are not knot-invariants. Finally, we will extend the paper a little by discussing corrections to all orders in $\hbar$.
Papers:

Date: 19 February 2021, 1.30 - 3.00 pm
Location: Zoom

More on holographic correlators: Twisted and dimensionally reduced structures

Speaker: Andrea Manenti
Papers:

• More on holographic correlators: Twisted and dimensionally reduced structures 2101.04114

Date: 05 February 2021, 1.30 - 3.00 pm
Location: Zoom

Celestial Amplitudes and the Double Copy

Speaker: Lucia Garozzo
Abstract: Celestial amplitudes are obtained by performing a change of basis on traditional scattering amplitudes. They behave as conformal correlators, giving rise to the speculation that there is a CFT living on the celestial sphere at the null boundary of flat spacetime, and thus a possible holographic description of flat space quantum gravity. I will give an overview of the topic and present the result of the paper 2007.15027, where the authors find a simple prescription to relate gauge theory and gravity celestial amplitudes at tree level.
Papers:

• A Double Copy for Celestial Amplitudes 2007.15027

Date: 22 January 2021, 1.30 - 3.00 pm
Location: Zoom

## TALKS - FALL 2020

Exploring standard like models
Speaker: Robin Schneider

Papers:

• Explore and Exploit with Heterotic Line Bundle Models 2003.04817

Date: 03 December 2020, 1.30 - 3.00 pm
Location: Zoom

Large p explorations. From SUGRA to big STRINGS in Mellin space
Speaker: Giulia Fardelli

Papers:

• Large p explorations. From SUGRA to big STRINGS in Mellin space 2007.09176

Date: 20 November 2020, 1.30 - 3.00 pm
Location: 80101, Zoom

What can Spinning Particles say about Kerr Black Holes?
Speaker: Paolo Pichini

Papers:

• From Scattering Amplitudes to Classical Physics: Universality, Double Copy and Soft Theorems 1903.12419
• Tree-Level Unitarity Constraints on the Gravitational Couplings of Higher-Spin Massive Fields 9408073

Date: 13 November 2020, 1.30 - 3.00 pm
Location: 80101, Zoom

Double copy in string and field theories
Speaker: Yong Zhang

Date: 6 November 2020, 1.30 - 3.00 pm
Location: 80101, Zoom

Superconformal kinematics in four dimensions
Speaker: Andrea Manenti

Papers:

• Differential operators for superconformal correlation functions 1910.12869
• R-current three-point functions in 4d N=1 superconformal theories 1804.09717
• Implications of ANEC for SCFTs in four dimensions 1905.09293

Date: 23 October 2020, 1.30 - 3.00 pm
Location: Häggsalen, Zoom

Computing (multiloop) Feynman integrals through analytic and numerical methods
Speaker: Martijn Hidding
Papers:

• All orders structure and efficient computation of linearly reducible elliptic Feynman integrals 1712.04441
• Evaluating two-loop non-planar master integrals for Higgs + jet production with full heavy-quark mass dependence 1907.13156
• The complete set of two-loop master integrals for Higgs + jet production in QCD 1911.06308
• DiffExp, a Mathematica package for computing Feynman integrals in terms of one-dimensional series expansions 2006.05510

Date: 16 October 2020, 1.30 - 3.00 pm
Location: Polhemsalen, Zoom

On-shell constructions of nonlinear sigma model
Speaker: Zhewei Yin

Date: 09 October 2020, 1.30 - 3.00 pm
Location: Häggsalen, Zoom

Vertex operators for the 11D pure spinor superparticle
Speaker: Max Guillen

Date: 02 October 2020, 1.30 - 3.00 pm
Location: Polhemsalen, Zoom

Introducing 3d N=1 QFTs

Date: 25 September 2020, 1.30 - 3.00 pm
Location: ITC room 2247, Zoom

## Talks - Spring 2020

Fermionic Localization of the Schwarzian Theory
Speaker: Lorenzo Ruggeri
Papers:

• Fermionic Localization of the Schwarzian Theory 1703.04612
• Conformal symmetry and its breaking in two dimensional Nearly Anti-de-Sitter space 1606.01857

Date: 11 March 2020, 1.30 - 3.00 pm
Location: Room Å80101

Stringy Canonical Forms
Speaker: Fei Teng
Papers:

Date: 06 March 2020, 1.30 - 3.00 pm
Location: Room Å4003

Sphere Packing and Quantum Gravity II
Speaker: Alexander Söderberg
Papers:

Date: 28 February 2020, 1.30 - 3.00 pm
Location: Room Å4003

Walls, Anomalies, and (De)Confinement in Quantum Anti-Ferromagnets
Speaker: Arash Arabi Ardehali
Papers:

• Walls, Anomalies, and (De)Confinement in Quantum Anti-Ferromagnets 1706.05731

Date: 21 February 2020, 1.30 - 3.00 pm
Location: Room Å4003

Sphere Packing and Quantum Gravity
Speaker: Alexander Söderberg
Papers:

Date: 14 February 2020, 1.30 - 3.00 pm
Location: Room Å4003

Froissart bound for/from CFT Mellin amplitudes
Speaker: Parijat Dey
Papers:

• Froissart bound for/from CFT Mellin amplitudes: 1911.05974

Date: 07 February 2020, 1.30 - 3.00 pm
Location: Room Å4003

GSO projections via SPT phases
Speaker: Luca Cassia
Papers:

• GSO projections via SPT phases: 1908.04805
• Topological Superconductors on Superstring Worldsheets: 1911.11780

Date: 24 January 2020, 1.30 - 3.00 pm
Location: Room Å4003

Higher U(1) Charge Models in type IIB and their F-theory lift
Speaker: Damián K. Mayorga Pena
Abstract:
We construct models with U(1) gauge group and matter with charges up to 6, in the context of type IIB compactifications. We show explicitly that models with charges up to 4 can be derived from corresponding models in F-theory by applying the Sen weak coupling limit. We derive which type IIB models should be the limit of charge 5 and 6 F-theory models. Explicit six dimensional type IIB models with maximal charge 5 and 6 are constructed on an algebraic K3 surface that is the double cover of CP2. By using type IIB results we are also able to rediscover the F-theory charge 4 model in a straightforward way.
Date: 15 January 2020, 1.30 - 3.00 pm
Location: Room Å80101