YOUNGST@RS - Supergravity and Holography

Europe/Berlin
Mainz Institute for Theoretical Physics, Johannes Gutenberg University

Mainz Institute for Theoretical Physics, Johannes Gutenberg University

Virtual Workshop
Description

The unification of quantum principles with gravity into a consistent theory of quantum gravity is one of the main challenges of modern theoretical physics.

In this context, several approaches based on different motivations and techniques have been developed. Among them, supergravity and string theory turned out to be complementary approaches to quantum gravity. The former, being a low-energy effective theory for the massless excitations of superstring theory, is realized as a supersymmetric extension of general relativity, where invariance under general coordinate transformations follows from supersymmetry itself.

In this scenario, it becomes of crucial importance to single out the essential features shared by different approaches which may then benefit from the mutual interchange of tools and ideas. In this respect, one of the major recent development concerns the holographic principle, of which one of the most celebrated realizations is the AdS/CFT correspondence (also known as gauge/gravity duality). The holographic principle was originally motivated by black hole physics and in particular by the peculiar property of their entropy scaling with the horizon area rather than with their volume, as one would instead expect being entropy an extensive quantity. Essentially, the holographic principle states that gravitational physics significantly reduces the number of physical degrees of freedom, suggesting that a quantum gravity theory must be fundamentally non-local in the sense that all the information about its degrees of freedom is encoded at the boundary surface, the latter being finite or asymptotic. It is widely expected that any good candidate quantum gravity theory should exhibit holographic features, at least in certain regimes. Although under the experimental point of view holography is still a hypothetical perspective, the study of holographic aspects of supergravity theories is a promising framework for connecting different approaches as well as for understanding to which extent holography might be realized at a fundamental level.

The scientific program of the workshop aims to bring together a diverse group of leading theorists in supergravity, black hole solutions, and holography, to forge collaborations between different areas, identify common subjects and complementary approaches, and set the agenda for future developments and new applications. The key focus areas will be:

  • Unconventional supersymmetry;
  • Recent advances in supergravity and applications in the context of holography;
  • Teleparallel supergravity;
  • Geometric approaches to supergravity in superspace;
  • Regularization methods in gravity;
  • Black hole solutions.

The participation of prominent experts will ensure top-quality research output, with significant impact on several sub-fields.

Contact @ MITP : Guest Relations Team
    • Welcome Greeting by MITP Directors
    • 1
      Jorge Zanelli: Local SUSY, and unconventional approach

      Abstract: Unconventional SUSY connects spacetime and internal symmetries, combining spin-1 gauge field and spin-1/2 fermions in a single Lie superalgebra-valued connection. In this representation, states do not come in Bose-Fermi pairs, avoiding the doubling of fields. If the local symmetry contains the Lorentz group, gravity is inevitably included, but there are no spin-3/2 (or higher) fundamental fields. The resulting systems are remarkably simple, closely resembling a standard quantum field theory and SUSY still emerges not as a symmetry of the action, but as a feature of the vacuum/ground state. Thus, local SUSY is a conditional/contingent symmetry, like Poincaré or AdS symmetries that depend on the nature of the spacetime background. We illustrate the general construction with 3D and 4D examples.

    • 16:00
      Break
    • 2
      Laura Andrianopoli: Unconventional supersymmetry and AdS_4 supergravity
    • 17:10
      Break
    • Discussion
    • 3
      Evelyn Rodríguez: Chern-Simons Supergravity theories with torsion and non-relativistic limit

      Abstract: Teleparallel gravity is an alternative theory of gravity known to be considered equivalent to General Relativity. However, they are conceptually quite different. In particular, the teleparallel formulation of gravity is described by a vanishing curvature and a non-vanishing torsion. In that case, the geometry is no longer Riemannian but corresponds to the so-called Riemann-Cartan geometry. In this talk, I will present a gauge-invariant three-dimensional teleparallel supergravity theory using the Chern-Simons (CS) formalism. The construction is based on a supersymmetric extension of a particular deformation of the Poincaré algebra. At the bosonic level the theory describes a non-Riemannian geometry with a non-vanishing torsion. I will also present a Maxwellian generalization of the teleparallel gravity, allowing to introduce a non-vanishing torsion to the Maxwell CS gravity. The non-relativistic version of the teleparallel CS (super)gravity theory will also be discussed.

    • 16:00
      Break
    • 4
      Pietro Antonio Grassi: The integral forms for the geometry of supergravity

      Abstract: The geometry of supergravity is extensively studied in two different frameworks:
      Superspace and Group Manifold Approach (a.k.a. Rheonomy).
      Both techniques have advantages and drawbacks, but apparently the integral forms are able to relate the two approaches fusing them within the geometry of supermanifolds.
      We present a short introduction to these new techniques and some applications to supergravity.

    • 17:10
      Break
    • Discussion
    • 5
      Rodrigo Olea: Conformal renormalization in AdS gravity

      Abstract: We present evidence that the renormalization of Einstein-AdS gravity can be derived from conformal structures in the bulk.
      In point of fact, by applying a holographic mechanism which reduces Conformal Gravity to its Einstein sector in 4 and 6 dimensions, the Einstein-AdS action is naturally endowed with the correct counterterms.

    • 16:00
      Break
    • 6
      Olivera Mišković: EGB supergravity and black holes with unbroken supersymmetries

      Abstract: We discuss supersymmetric extension of Einstein-Gauss-Bonnet AdS_5 gravity with a particular GB coupling. The theory admits black hole solutions with non-trivial topological properties, which are also BPS states that leave some of the supersymmetries unbroken. We analyse physical properties of the solutions, such as their conserved charges and topological numbers. We find many similarities of these solutions with standard supergravity black holes, and also with 3D BTZ geometries.

    • 17:10
      Break
    • Discussion