Meeting PRIN "String Theory as a bridge between Gauge Theories and Quantum Gravity"

15 Nov 2024, 14:00 → 16 Nov 2024, 14:00 Europe/Rome

Auditorium BPER

Lorenzo Bianchi (Istituto Nazionale di Fisica Nucleare), Marco Billo' (Istituto Nazionale di Fisica Nucleare), Marialuisa Frau (Istituto Nazionale di Fisica Nucleare), Alberto Lerda (Istituto Nazionale di Fisica Nucleare)

Friday 15 November

Roma Tor Vergata

Convener: Jose Francisco MORALES (Istituto Nazionale di Fisica Nucleare)

1 Gauge theory pictures of gravity and cosmology perturbations

I will review the SW gravity correspondence that relates solutions of the Heun equation, governing perturbations of black hole, D-brane, fuzzball, and cosmological backgrounds, to partition functions of quiver gauge theories. Some applications to the study of scattering amplitudes and post-Newtonian expansions of gravitational waves will be briefly illustrated.

Speaker: Jose Francisco Morales (Istituto Nazionale di Fisica Nucleare)

16:00 Coffee break

Torino

2 Localization as a bridge between String Theory and QFT

4d Yang-Mills theories with extended supersymmetry represent a playground for investigating non-perturbative features and techniques in QFT. Pestun showed that the path integral defining certain protected oservables, both local and non local, localizes to a matrix integral. This great simplification paves the road toward obtaining explicit results at strong coupling and making contact with holographic descriptions. The matrix model is gaussian in the maximally supersymmetric N=4 case, while for generic N=2 theories it has complicated interactions. We will describe the "full Lie Algebra" approach, developed mostly in our groups, to deal with it. It suggests an efficient organization of the perturbative expansion, both in conformal and non conformal cases. In conformal theories, it permits in many cases to resum the perturbative expansion and, in the 't Hooft linit, to extrapolate it to strong coupling. We describe the type of results and that can be obtained for correlators and integrated correlators involving chiral and antichiral operators as well as Wilson loops and their relation to the dual holographic realization.

Speaker: Marco Billo' (Istituto Nazionale di Fisica Nucleare)

3 An explicit example of exact results for a 4d N=2 SCFT: a Z_2 orbifold of N=4 SYM

We consider the 4d N=2 SCFT obtained by a Z_2 orbifold of N=4 SYM. By exploiting supersymmetric localization, we determine exact expressions for a broad set of observables, valid at any value of the ’t Hooft coupling in the planar limit of the theory. These observables include two-point and three-point correlation functions between chiral and anti-chiral operators, correlators among Wilson loops and integrated correlators. Using both analytical and numerical techniques we derive the strong coupling limit of these quantities. Where possible, we compare our findings with holographic predictions via the AdS/CFT correspondence.

Speaker: Alessandro Pini (Istituto Nazionale di Fisica Nucleare)

Saturday 16 November

Roma Sapienza

4 Rotating metrics and multipole moments from scattering amplitudes

We review how the vacuum metric generated by a generic rotating object is determined by computing the classical contribution of scattering amplitudes describing the graviton emission by massive particles with spin. By focusing on the case of spin 1, In D = 4 spacetime dimensions we recover the vacuum Hartle-Thorne solution describing a generic spinning object to second order in the angular momentum, of which the Kerr metric is a particular case obtained for a specific mass quadrupole moment dictated by the uniqueness theorem. In D > 4, the absence of black-hole uniqueness theorems implies that there are multiple spinning black hole solutions with different topology. Using scattering amplitudes, we find a generic solution depending on the mass, angular momenta, the mass quadrupole moment, and a new stress quadrupole moment which does not exist in D = 4. Inspired by this analysis, we derive the most general class of energy-momentum tensors associated with a given multipolar structure of the spacetime in arbitrary dimensions, working in momentum space and at linear order in the gravitational coupling. We derive directly from the energy-momentum tensor the full multipolar structure of any solution in complete analogy to Newtonian gravity.

Speaker: Fabio Riccioni (Istituto Nazionale di Fisica Nucleare)

5 Spectroscopy of topological stars

We present results on the linear response of four dimensional regular topological stars arising from Einstein-Maxwell theory in five dimensions. We discuss the stability of these solutions under both radial and nonradial perturbations, and the potential observational signatures of these objects.

Speaker: Alexandru Dima (Istituto Nazionale di Fisica Nucleare)

11:00 Coffee break

Trieste

6 Symmetry operators in holography.

The realization of charged operators in holography is an old subject. The prototypical example being baryons in the CFT, which are holographically realized by D3 branes ending on the boundary. In recent years the subject has shifted to how symmetry operators (i.e. topological operators) are described holographically. We will review this subject starting with the classical works and ending with the current discussion. Based on https://arxiv.org/abs/2407.00773

Speaker: Eduardo García Valdecasas Tenreiro (Istituto Nazionale di Fisica Nucleare)