Non-extremal superdescendants of the D1D5 CFT

We construct solutions of IIB supergravity dual to non-supersymmetric states of the D1D5 system. These solutions are constructed as perturbations carrying both left and right moving momentum around the maximally rotating D1D5 ground state at linear order. They are found by extending to the asymptotically flat region the geometry generated in the decoupling limit by the action of left and right R-currents on a known D1D5 microstate. The perturbations are regular everywhere and do not carry any global charge. We also study the near-extremal limit of the solutions and derive the first non-trivial correction to the extremal geometry.Comment: 25 page

AdS Vacuum Bubbles, Holography and Dual RG Flows

We explore the holographic properties of non-perturbative vacuum decay in Anti-de Sitter ($\mathrm{AdS}$) geometries. To this end, we consider a gravitational theory in a metastable $\mathrm{AdS}_3$ state, which decays into an $\mathrm{AdS}_3$ of lower vacuum energy via bubble nucleation, and we employ the Ryu-Takayanagi conjecture to compute the entanglement entropy $S_\text{ent}$ in its alleged holographic dual. Our analysis leads us to infer that the nucleation and growth of a vacuum bubble correspond, in the boundary theory, to the introduction of a relevant deformation and a subsequent Renormalization Group (RG) flow, where $S_\text{ent}$ provides a $c$-function. We provide further evidence for the claim and comment on the holographic interpretation of off-centred or multiple bubbles. We also frame the issue in the formalism of Holographic Integral Geometry, discussing the consequences on the structure of the holographic RG flow and recovering the standard holographic RG as a limiting case.Comment: 26 pages, 10 figures; references and comments adde

A Cloud-Native Web Application for Assisted Metadata Generation and Retrieval: THESPIAN-NER

Within the context of the Competence Centre for the Conservation of Cultural Heritage (4CH) project, the design and deployment of a platform-as-a-service cloud infrastructure for the first European competence centre of cultural heritage (CH) has begun, and some web services have been integrated into the platform. The first integrated service is the INFN-CHNet web application for FAIR storage of scientific analysis on CH: THESPIAN-Mask. It is based on CIDOC-CRM-compatible ontology and CRMhs, describing the scientific metadata. To ease the process of metadata generation and data injection, another web service has been developed: THESPIAN-NER. It is a tool based on a deep neural network for named entity recognition (NER), enabling users to upload their Italian-written report files and obtain labelled entities. Those entities are used as keywords either to serve as (semi)automatically custom queries for the database, or to fill (part of) the metadata form as a descriptor for the file to be uploaded. The services have been made freely available in the 4CH PaaS cloud platform

Unitary 4-point correlators from classical geometries

SCOAP

A note on the Virasoro blocks at order 1/c

We derive an explicit expression for the $1/c$ contribution to the Virasoro blocks in 2D CFT in the limit of large $c$ with fixed values of the operators' dimensions. We follow the direct approach of orthonormalising, at order $1/c$, the space of the Virasoro descendants to obtain the blocks as a series expansion around $z=0$. For generic conformal weights this expansion can be summed in terms of hypergeometric functions and their first derivatives with respect to one parameter. For integer conformal weights we provide an equivalent expression written in terms of a finite sum of undifferentiated hypergeometric functions. These results make the monodromies of the blocks around $z=1$ manifest.Comment: 13 pages; v2: added references to previous wor

Black hole microstates and the information paradox

In this thesis we describe the fuzzball proposal within the context of string theory. Part I is devoted to the introduction of the subject. In Part II we build new microstate solutions. In Part III we use holography as a tool

Black hole microstates and the information paradox

In this thesis we describe the fuzzball proposal within the context of string theory. Part I is devoted to the introduction of the subject. In Part II we build new microstate solutions. In Part III we use holography as a tool

General supersymmetric AdS5\hbox {AdS}_5 black holes with squashed boundary

International audienceWe present a new family of asymptotically locally $\hbox {AdS}_5$ squashed supersymmetric black hole solutions of Fayet–Iliopoulos gauged ${{{\mathcal {N}}}}=2$ , $D=5$ supergravity with two vector multiplets that have a natural uplift to type IIB supergravity. Our new family of black holes is characterized by three parameters, of which two control the horizon geometry while the latter regulates the squashing at the boundary. We evaluate the main physical properties of the family of solutions using holographic renormalization and find that the entropy is independent on the squashing and it is reproduced by using the angular momentum and the Page charges. In previously known solutions Page and holographic charges are equal, due to the vanishing of the Chern–Simons term that here, instead, is relevant. This result suggests that for asymptotically locally $\hbox {AdS}_5$ solutions we should refer to the Page charges to describe the thermodynamics of the system

Holographic entanglement entropy and complexity of microstate geometries

We study holographic entanglement entropy and holographic complexity in a two-charge, 1/4-BPS family of solutions of type IIB supergravity, controlled by one dimensionless parameter. All the geometries in this family are asymptotically AdS3 ×3 ×4 and, varying the parameter that controls them, they interpolate between the global AdS3 × 3 × 4 and the massless BTZ3 × 3 × 4 geometry. Due to AdS/CFT duality, these geometries are dual to pure CFT heavy states. We find that there is no emergence of entanglement shadow for all the values of the parameter and we discuss the relation with the massless BTZ result, underlying the relevance of the nature of the dual states. We also compute the holographic complexity of formation of these geometries, finding a nice monotonic function that interpolates between the pure AdS3 result and the massless BTZ one