Registration Room: Physics Department - Aula Amaldi (Marconi Building)

Welcome

• Massimo Bianchi (Istituto Nazionale di Fisica Nucleare)

Room: Physics Department - Aula Amaldi (Marconi Building)

Quantum Cross-section of Near-extremal Black Holes

• Roberto Alejandro Emparan Garcia De Salazar

Room: Physics Department - Aula Amaldi (Marconi Building) We explore how to detect the large quantum fluctuations in the throat of a near-extremal black hole, where the dynamics are governed by the Schwarzian theory. To this end, we scatter a low-frequency wave of a massless, minimal scalar off the black hole and calculate the absorption cross-section. We find that in the strongly coupled regime the absorption cross-section exceeds the semiclassical prediction. We conclude that a measurement showing an enhanced absorption cross-section serves as a clear signature of the large quantum fluctuations in the geometry.

Themelia, spikes, bulges, black poles, scars … and what they teach us about black holes

• Iosif Bena

Room: Physics Department - Aula Amaldi (Marconi Building)

Can We Observe the Breakdown of Effective Field Theory at Black Hole Horizons?

• Daniel Mayerson

Room: Physics Department - Aula Amaldi (Marconi Building)

What is the Bridge between Gauge Theories and Quantum Gravity at low Energies?

• Jan de Boer

Room: Physics Department - Aula Amaldi (Marconi Building)

Spinning up the black hole – string correspondence

• Andrea Puhm

Room: Physics Department - Aula Amaldi (Marconi Building) The correspondence principle between strings and black holes is a general framework for matching black holes and massive states of fundamental strings at a point where their physical properties (such as mass, entropy and temperature) smoothly agree with each other. As such it offers a statistical interpretation of black hole entropy. I will discuss the extension of this correspondence principle to rotating black holes and strings. Several puzzles arise when attempting to include rotation, but they can be resolved by adding novel ingredients to the correspondence: dynamical features, non-stationary configurations and shapes of strings and black holes. As a test of this proposal I will compare the sizes of rotating strings and black holes for small, typical, and large values of the angular momentum.

Novel AdS vacua from dynamical open strings

• Giuseppe Sudano (Istituto Nazionale di Fisica Nucleare)

Room: Physics Department - Aula Amaldi (Marconi Building) We consider massive type IIA Supergravity compactified down to 4 dimensions on twisted tori or down to 7 dimensions on a 3-sphere, in presence of D6 branes and O6 planes. Both these instances admit a gauged Supergravity description, with a quadratic potential in the embedding tensor components. The dynamics of open strings is taken into account by adding extra vector multiplets and embedding tensor components. The scalar potential gets new terms that in 4 dimensions can be matched with contributions coming from dimensional reduction of the non-Abelian DBI and WZ brane actions. The uplift of 7-dimensional solutions to 10 dimensions is instead analyzed at the level of equations of motion, since no consistent truncation from massive type IIA down to 7 dimensions is known with an arbitrary number of vector multiplets. Novel AdS4 and AdS7 vacua are determined, both supersymmetric and non-supersymmetric. Their perturbative stability has been addressed by computing their mass spectra. Some of the vacua are found to be perturbatively stable, despite their being non -supersymmetric.

The i-epsilon Prescription for String Amplitudes and Regularised Modular Integrals

• Jan Manschot

Room: Physics Department - Aula Amaldi (Marconi Building) I will discuss one-loop amplitudes in string theory, and in particular their analytic continuation based on a string theoretic analog of the i-epsilon prescription of quantum field theory. For various zero- and two-point one-loop amplitudes of both open and closed strings, I will explain that this analytic continuation is equivalent to a regularization using generalized exponential integrals. Our approach provides exact expressions in terms of the degeneracies at each mass level. Based on joint work with Zhi-Zhen Wang.

Non-BPS branes as holographic symmetry operators

• Diego Rodriguez Gomez

Room: Physics Department - Aula Amaldi (Marconi Building) We propose a holographic description of the operators implementing continuous global symmetries that are dual to superstring gauge fields in terms of non-BPS D- branes, and consider some possible further extensions.

Integrated correlators in a N=2 SYM theory with fundamental flavors

• Paolo Vallarino (Università di Torino)

Room: Physics Department - Aula Amaldi (Marconi Building) I will discuss recent developments in the study of integrated 4-point correlators of primary operators in a four-dimensional \mathcal{N}=2 superconformal field theory with SU(N) gauge group and matter in the fundamental and anti-symmetric representations. Exploiting supersymmetric localization, it is possible to map the computation of these correlators to an interacting matrix model and obtain expressions that are valid for any value of the ’t Hooft coupling in the large-N limit of the theory. In particular, I will focus on the strong-coupling regime, showing how to extract analytically the strong-coupling expansion of the integrated correlators from these exact expressions.

The future of Cosmic Microwave Background measurements

• Paolo De Bernardis (Istituto Nazionale di Fisica Nucleare)

Room: Physics Department - Aula Amaldi (Marconi Building)

From Holographic Correlators in the Sky to Euclidean AdS

• Charlotte Sleight (Istituto Nazionale di Fisica Nucleare)

Room: Physics Department - Aula Amaldi (Marconi Building)

The AdS4 × CP3 Virasoro-Shapiro Amplitude

• Tobias Hansen

Room: Physics Department - Aula Amaldi (Marconi Building) I will present the derivation of the AdS Virasoro-Shapiro amplitude for the scattering of gravitons in type IIA string theory on AdS4xCP3. This is achieved by combining the structure of the OPE in the AdS/CFT dual ABJM theory with an ansatz for the amplitude as a string worldsheet integral over single-valued polylogarithms. In this way we fix the first two curvature corrections, which satisfy consistency checks in the high energy limit, the low energy expansion as previously fixed using supersymmetric localisation, and for the dimensions of the exchanged massive string operators, some of which have been independently computed using integrability. We also predict the strong coupling dimensions of some operators which have not been previously studied using integrability.

Gravitational Waves form a quantum-field-theory perspective

• Jan Steinhoff

Room: Physics Department - Aula Amaldi (Marconi Building) This talk discusses how quantum-field-theory methods can be applied to model (classical) gravitational waves, in particular tidal effects, spin effects, and effects beyond general relativity.

S-matrix tools for bound waveform modelling

• Riccardo Gonzo (University of Edinburgh)

Room: Physics Department - Aula Amaldi (Marconi Building) We will show how scattering orbits can inform bound-orbit models, allowing to harness the power of the S-matrix to construct gravitational waveforms relevant for the dynamics of compact binary systems. First, I will derive the radial action from the worldline formalism, focusing for simplicity on the probe limit in a Kerr background. Then, I will show that such radial action (and the S-matrix) is a natural generating functional of classical observables, which provide a direct analytic continuation between a novel on-shell basis of scattering (time delay, elapsed proper time and deflection angle) and bound (radial frequency, averaged redshift and periastron advance) observables. Including radiation, we will then derive a new surprising map between scattering and bound waveforms, which is inspired and confirmed by Post-Newtonian calculations with time-domain multipoles. Finally, I will discuss some ongoing effort in trying to extend this map at 1SF order (with non-local-in-time hereditary effects) order using a novel geometric approach to the scattering-to-bound dictionary.

Source Multipoles and Energy-Momentum Tensors for Spinning Black Holes and Other Compact Objects

• Claudio Gambino (Istituto Nazionale di Fisica Nucleare)

Room: Physics Department - Aula Amaldi (Marconi Building) Inspired by the scattering amplitude program applied to General Relativity, we define the most general energy-momentum tensor constructed from mass and spin in momentum space and arbitrary dimensions. Through this approach, we establish a one-to-one correspondence between the form factors that characterize the source and the gravitational multipole moments of the induced spacetime, providing a precise definition of source multipoles in a relativistic context and identifying a new class of multipoles, which we call “stress multipoles”. We then apply this formalism to determine the source of rotating black holes and subsequently use it to construct horizonless Kerr mimickers.

Quantum Field Theory on AdS

• Elias Kiritsis

Room: Physics Department - Aula Amaldi (Marconi Building)

A compendium of logarithmic corrections in AdS/CFT

• Nikolay Bobev

Room: Physics Department - Aula Amaldi (Marconi Building) I will discuss logarithmic corrections to various CFT partition functions in the context of the AdS_4/CFT_3 correspondence for theories arising on the worldvolume of M2-branes. I will use four-dimensional gauged supergravity and heat kernel methods to derive general expressions for the logarithmic corrections to the gravitational on-shell action or black hole entropy for a number of different supergravity backgrounds. I will outline several subtleties and puzzles in these calculations and will show how they provide non-trivial precision tests of the AdS/CFT correspondence. These results have important implications for the existence of scale separated AdS vacua in string theory and for effective field theory in AdS more generally.

Continuous TQFTs and non-invertible symmetries

• Riccardo Argurio

Room: Physics Department - Aula Amaldi (Marconi Building)

Symmetry Breaking from Monopole Condensation in 3d QED

• Pierluigi Niro

Room: Physics Department - Aula Amaldi (Marconi Building) QED in 2+1 dimensions is among the simplest and yet very rich examples of strongly interacting gauge theories, arising in many physical contexts. When the number of electrons is large, the theory is known to flow to a symmetry-preserving interacting CFT at low energies, but this scenario is excluded below some critical value of the number of electrons. Focusing on the case of two electrons, we argue that the theory must then spontaneously break its U(2) global symmetry to a U(1) subgroup via the condensation of monopole operators. This gives rise to a non-linear sigma model with target space a squashed three-sphere, equipped with a theta term required by anomaly matching.

Viviana Fafone

• Viviana Fafone (Istituto Nazionale di Fisica Nucleare)

Room: Physics Department - Aula Amaldi (Marconi Building)

Matrix-Models/Large-Charge Duality at Higher Ranks

• Alba Grassi

Room: Physics Department - Aula Amaldi (Marconi Building)

Lessons from Non-Supersymmetric Strings

• Augusto Sagnotti (PI)

Room: Physics Department - Aula Amaldi (Marconi Building)

Closing and good-byes Room: Physics Department - Aula Amaldi (Marconi Building)