String Theory as a Bridge between Gauge Theory and Quantum Gravity

17 Feb 2025, 08:30 → 19 Feb 2025, 18:30 Europe/Rome

Physics Department - Aula Amaldi (Marconi Building) (Sapienza University of Rome)

Alberto Lerda (Istituto Nazionale di Fisica Nucleare), Fabio Riccioni (Istituto Nazionale di Fisica Nucleare), Marialuisa Frau (Istituto Nazionale di Fisica Nucleare), Massimo Bianchi (Istituto Nazionale di Fisica Nucleare), Matteo Bertolini (SISSA), Paolo Pani (Sapienza University of Rome & INFN Roma1)

The final event of the PRIN (Italian Research Project of National Interest) "String Theory as a Bridge between Gauge Theory and Quantum Gravity" will be a three-day conference that will take place at Sapienza University of Rome from 17 to 19 February 2025.

The event will be streamed on Zoom.

 

This project is a collaboration between theoretical physics groups at INFN, SISSA, University of Roma Tor Vergata, Turin University, University of Piemonte Orientale, and Sapienza University of Rome.

The topics of the workshop will range from gravitational wave phenomenology to modern approaches to scattering amplitudes, from quantum field theories in the presence of defects to the construction of novel theories with (broken) superconformal symmetry, from cosmological perturbations to highly excited strings and black-hole microstates.

List of invited speakers:

Riccardo Argurio
Iosif Bena
Paolo de Bernardis
Jan de Boer
Nikolay Bobev
Roberto Emparan
Viviana Fafone
Claudio Gambino
Alba Grassi
Riccardo Gonzo
Tobias Hansen
Elias Kiritsis
Jan Manschot
Daniel Mayerson
Pierluigi Niro
Andrea Puhm
Diego Rodriguez Gomez
Augusto Sagnotti
Charlotte Sleight
Jan Steinhoff
Giuseppe Sudano
Paolo Vallarino

 

 

 

Scientific Secretariat: Alessandra Curto  
Organizing Committee: Matteo Bertolini, Massimo Bianchi, Marialuisa Frau, Alberto Lerda, Paolo Pani

Local Organizing Committee: Fabrizio Corelli, Alexandru Dima, Paolo Pani, Fabio Riccioni

Support: This event is supported by INFN, Sapienza, and by MUR (Italian Ministry of University and Research) through the Grant 2020KR4KN2.

 

      

           

 

Monday, 17 February

08:45 → 09:15 Registration

09:15 → 09:30 Welcome

Speaker: Massimo Bianchi (Istituto Nazionale di Fisica Nucleare)

09:30 → 10:15 Quantum Cross-section of Near-extremal Black Holes

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.

Speaker: Roberto Alejandro Emparan Garcia De Salazar

QCross_Rome.pdf

10:15 → 11:00 Themelia, spikes, bulges, black poles, scars … and what they teach us about black holes

Speaker: Iosif Bena

11:00 → 11:30 Coffee Break

11:30 → 12:15 Can We Observe the Breakdown of Effective Field Theory at Black Hole Horizons?

Speaker: Daniel Mayerson

Presentation Mayerson 17-02-25.pdf

12:15 → 13:00 What is the Bridge between Gauge Theories and Quantum Gravity at low Energies?

Speaker: Jan de Boer

rome0225b.pdf

13:15 → 15:15 Lunch

15:15 → 16:00 Spinning up the black hole – string correspondence

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.

Speaker: Andrea Puhm

BHstring.pdf

16:00 → 16:45 Novel AdS vacua from dynamical open strings

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.

Speaker: Giuseppe Sudano (Istituto Nazionale di Fisica Nucleare)

Novel AdS vacua from dynamical open strings.pdf

16:45 → 17:30 The i-epsilon Prescription for String Amplitudes and Regularised Modular Integrals

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.

Speaker: Jan Manschot

Rome2025.pdf

17:30 → 19:15 Wine & Cheese

Tuesday, 18 February

09:00 → 09:45 Non-BPS branes as holographic symmetry operators

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.

Speaker: Diego Rodriguez Gomez

Non-BPSAndSymmetriesRome.pdf

09:45 → 10:30 Integrated correlators in a N=2 SYM theory with fundamental flavors

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.

Speaker: Paolo Vallarino (Università di Torino)

Vallarino_talk.pdf

10:30 → 11:10 Coffee Break

11:10 → 11:55 The future of Cosmic Microwave Background measurements

Speaker: Paolo De Bernardis (Istituto Nazionale di Fisica Nucleare)

11:55 → 12:40 From Holographic Correlators in the Sky to Euclidean AdS

Speaker: Charlotte Sleight (Istituto Nazionale di Fisica Nucleare)

Sleight Roma.pdf

12:40 → 14:30 Lunch

14:30 → 15:15 The AdS4 × CP3 Virasoro-Shapiro Amplitude

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.

Speaker: Tobias Hansen

hansen_rome.pdf

15:15 → 16:00 Gravitational Waves form a quantum-field-theory perspective

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.

Speaker: Jan Steinhoff

rome25.pdf

16:00 → 16:40 Coffee Break

16:40 → 17:25 S-matrix tools for bound waveform modelling

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.

Speaker: Riccardo Gonzo (University of Edinburgh)

Rome_workshop_RG.pdf

17:25 → 18:10 Source Multipoles and Energy-Momentum Tensors for Spinning Black Holes and Other Compact Objects

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.

Speaker: Claudio Gambino (Istituto Nazionale di Fisica Nucleare)

Sapienza25.pdf

Wednesday, 19 February

09:00 → 09:45 Quantum Field Theory on AdS

Speaker: Elias Kiritsis

Kiritsis-Rome-2025-light.pdf

09:45 → 10:30 A compendium of logarithmic corrections in AdS/CFT

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.

Speaker: Nikolay Bobev

Roma2025.pdf

10:30 → 11:10 Coffee Break

11:10 → 11:55 Continuous TQFTs and non-invertible symmetries

Speaker: Riccardo Argurio

roma25.pdf

11:55 → 12:40 Symmetry Breaking from Monopole Condensation in 3d QED

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.

Speaker: Pierluigi Niro

Talk_Niro.pdf

12:40 → 14:10 Lunch

14:10 → 14:55 Viviana Fafone

Speaker: Viviana Fafone (Istituto Nazionale di Fisica Nucleare)

14:55 → 15:40 Matrix-Models/Large-Charge Duality at Higher Ranks

Speaker: Alba Grassi

matrixmodelhigehrrank_Rome.pdf

15:40 → 16:20 Coffee Break

16:20 → 17:05 Lessons from Non-Supersymmetric Strings

Speaker: Augusto Sagnotti (PI)

Roma_2025_pdf.pdf

17:05 → 17:25 Closing and good-byes