The DRM-String transition and the Supergroup story

• Ferdinando Gliozzi (INFN, Turin)

Room: FB53

QCDing with Paolo: a break from the string

• Gabriele Veneziano (College de France & CERN)

Room: FB53

Loop Amplitudes in String Theory

• Alberto Lerda (INFN, Turin)

Room: FB53

D-branes and gauge/gravity correspondence

• Marialuisa Frau (INFN, Turin)

Room: FB53

Superstring Amplitudes: From Threshold Effects to Soft Theorems and Back?

• Raffaele Marotta (INFN, Naples)

Room: FB53

Gravitational scattering at high energies

• Rodolfo Russo (QMUL)

Room: FB53

Filling the gaps

• Paolo Di Vecchia (Nordita)

Room: FB53

The Rise of the Octagon - Towards the gravity dual of dynamical supersymmetry breaking

• Matteo Bertolini (SISSA, Trieste)

In the context of the gauge/gravity correspondence I will present a model where supersymmetry is broken dynamically into stable vacua. This is based on a system of D-branes placed at the tip of the so-called Octagon singularity and represents the first such instance within the correspondence. The model fills a gap in top-down stringy descriptions of the diverse phases and IR dynamics that supersymmetric gauge theories can enjoy, and paves the way for a gravity/geometric dual of dynamical supersymmetry breaking. The relevance of this result in the wider context of the string landscape and the swampland program will also be discussed.

Towards higher multiplicity 2-loop string amplitudes

• Eric D'Hoker (UCLA)

Progress is made towards the evaluation of superstring amplitudes of higher multiplicity at two loops and beyond by reducing the spin structure dependence of worldsheet correlators to that of certain modular tensors. For two loops, a system of trilinear relations obeyed by these modular tensors allows the evaluation of the spin structure sums for arbitrary multiplicity.

Stringy effects in the holographic description of the N=2 SCFT quiver theory

• Marco Billo (INFN, Turin)

We consider a $\mathcal{N}=2$ SCFT in $d=4$ described by a circular quiver with $M$ nodes. The protected chiral single traces can be organized in unwtisted and twisted operators. The structure constants of such operators can be computed at large $N$ using localization and the result can be continued towards strong 't Hooft coupling. In this regime we can check it against the holographic description of the theory on $AdS_5 \times S_5/Z_M$. The untwisted and twisted/untwisted structure constants are precisely accounted for by the Witten diagrams derived from the supergravity lagrangian. In the case of the structure constants involving only twisted operators - which in the gauge theory side is on par with the other cases - the needed cubic vertices should come instead from higher derivative corrections due to the interaction of three twisted closed strings. Preliminary results indicate that this is indeed the case.

Classical Higher-Spin Amplitudes and Kerr Black Holes

• Lucile Cangemi (Uppsala University)

I will discuss the role of gauge symmetry for constraining Kerr dynamics. EFTs for both Kerr black holes and the closely related electromagnetic root-Kerr solution are considered using Stückelberg fields. This uniquely predicts the known Kerr three-point amplitudes to all spin using Ward identities that follow from massive gauge symmetry. I will also discuss aspects relevant to the analysis of the spin-s Compton amplitude and provide some explicit all-spin results for the non-Abelian root-Kerr Compton amplitude.

Binary dynamics of spinning black holes in the Post-Minkowskian regime

• Francesco Alessio (Nordita)

I will discuss different aspects and approaches to the Kerr binary problem using scattering amplitudes techniques. In particular, I will start by showing the construction of a Lagrangian relevant to describe Kerr binaries, deriving expressions for the classical amplitude for the elastic 2—>2 process at 1PM and 2PM. I will then consider radiation reaction effects and their connection to the imaginary part of the 3PM spinning eikonal phase. Eventually, I will mention partial new results for the Compton amplitude involving spinning objects coming from string theory.

Inelastic exponentiation and gravitational waveforms

• Carlo Heissenberg (Uppsala University)

The classical limit of scattering amplitudes provides a convenient strategy to calculate gravitational observables associated to black-hole encounters. Taking this limit requires a resummation in the effective coupling, known as the eikonal exponentiation. In this talk, I will present recent progress on the operator version of this exponentiation, which combines elastic (two-to-two) with inelastic (two-to-three) channels to produce a unitary description of the scattering process. I will illustrate how including tree-level and one-loop contributions to the eikonal operator allows us to access the leading and subleading waveforms describing the gravitational waves produced during a black-hole scattering process. The latter involve the so-called tail effects, whereby the emitted gravitational radiation can re-scatter against the curvature induced by each black hole.