scholarly journals On the Geometric Approach to the Boundary Problem in Supergravity

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 463
Author(s):  
Laura Andrianopoli ◽  
Lucrezia Ravera
Keyword(s):  
Cosmological Constant ◽  
Boundary Problem ◽  
Geometric Approach ◽  
Geometric Construction ◽  
Boundary Values ◽  
Negative Cosmological Constant ◽  
Boundary Terms ◽  
Bonnet Term ◽  
Topological Boundary ◽  
Field Strengths

We review the geometric superspace approach to the boundary problem in supergravity, retracing the geometric construction of four-dimensional supergravity Lagrangians in the presence of a non-trivial boundary of spacetime. We first focus on pure N=1 and N=2 theories with negative cosmological constant. Here, the supersymmetry invariance of the action requires the addition of topological (boundary) contributions which generalize at the supersymmetric level the Euler-Gauss-Bonnet term. Moreover, one finds that the boundary values of the super field-strengths are dynamically fixed to constant values, corresponding to the vanishing of the OSp(N|4)-covariant supercurvatures at the boundary. We then consider the case of vanishing cosmological constant where, in the presence of a non-trivial boundary, the inclusion of boundary terms involving additional fields, which behave as auxiliary fields for the bulk theory, allows to restore supersymmetry. In all the cases listed above, the full, supersymmetric Lagrangian can be recast in a MacDowell-Mansouri(-like) form. We then report on the application of the results to specific problems regarding cases where the boundary is located asymptotically, relevant for a holographic analysis.

scholarly journals Non-Abelian gravitating solitons with negative cosmological constant

2004 ◽  
Vol 21 (6) ◽  
pp. 1667-1683 ◽  
Author(s):  
Peter Breitenlohner ◽  
Dieter Maison ◽  
George Lavrelashvili
Keyword(s):  
Cosmological Constant ◽  
Negative Cosmological Constant

scholarly journals Global monopole metric in 2 + 1 dimensions

2019 ◽  
Vol 16 (01) ◽  
pp. 1950006
Author(s):  
S. Habib Mazharimousavi ◽  
M. Halilsoy
Keyword(s):  
Exact Solution ◽  
Cosmological Constant ◽  
Electric Charge ◽  
Radial Distance ◽  
Series Solutions ◽  
Global Monopole ◽  
Negative Cosmological Constant ◽  
Consistent Manner ◽  
Positive Integers

In order to obtain the geometry of a global monopole without cosmological constant and electric charge in [Formula: see text] dimensions, we make use of the broken [Formula: see text] symmetry. In the absence of an exact solution, we determine the series solutions for both the metric and monopole functions in a consistent manner that satisfies all equations in appropriate powers. The new expansion elements are of the form [Formula: see text] for the radial distance [Formula: see text] and positive integers [Formula: see text] and [Formula: see text] constrained by [Formula: see text]. To the lowest order of expansion, we find that in analogy with the negative cosmological constant the geometry of the global monopole acts repulsively, i.e. in the absence of a cosmological constant the global monopole plays at large distances the role of a negative cosmological constant.

scholarly journals Central charges for AdS black holes

2021 ◽  
Author(s):  
Malcolm Perry ◽  
Maria J Rodriguez
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cosmological Constant ◽  
Central Charge ◽  
Negative Cosmological Constant ◽  
Ads Black Holes ◽  
Kerr Black Holes ◽  
Distinguishing Features ◽  
Area Law ◽  
Cardy Formula

Abstract Nontrivial diffeomorphisms act on the horizon of a generic 4D black holes and create distinguishing features referred to as soft hair. Amongst these are a left-right pair of Virasoro algebras with associated charges that reproduce the Bekenstein-Hawking entropy for Kerr black holes. In this paper we show that if one adds a negative cosmological constant, there is a similar set of infinitesimal diffeomorphisms that act non-trivially on the horizon. The algebra of these diffeomorphisms gives rise to a central charge. Adding a boundary counterterm, justified to achieve integrability, leads to well-defined central charges with cL = cR. The macroscopic area law for Kerr-AdS black holes follows from the assumption of a Cardy formula governing the black hole microstates.

Is the Massive Graviton a Viable Possibility?

2003 ◽  
Vol 18 (supp01) ◽  
pp. 329-339
Author(s):  
Antonios Papazoglou
Keyword(s):  
Cosmological Constant ◽  
Brane World ◽  
Massive Graviton ◽  
Curved Space ◽  
Negative Cosmological Constant ◽  
World Theory ◽  
Six Dimensions

In this talk we discuss the scenario of multigravity according to which the gravity we observe in intermediate scales (1 mm < r < 1026 cm ) is mediated by both a massless graviton and one or more of ultralight spin-2 state. We present how this can be realized in a five dimensional brane-world theory with flat branes and the complications associated with the extra polarizations of the massive gravitons (van Dam-Veltman-Zakharov discontinuity) and the ghost radions corresponding to the fluctuations of the negative tension branes present in these models. We then show how we can construct models of AdS4 branes instead with exclusively positive tension and demonstrate how the van Dam-Veltman-Zakharov no-go theorem can be circumvented in curved space. These models, although they are consistent, face phenomenological problems related to the presence of a remnant negative cosmological constant on the branes. We finally present how we can obtain the same constructions in six dimensions with flat positive tensions branes only, in a manner that they are both theoretically consistent and phenomenologically acceptable. The latter come in two copies each and offer the first problem-free realization of the multigravity scenario.

scholarly journals The invalidity of “negative mass” description of the dark sector

2019 ◽  
Vol 34 (35) ◽  
pp. 1975002
Author(s):  
A. Stepanian
Keyword(s):  
General Relativity ◽  
Cosmological Constant ◽  
Observational Data ◽  
Weak Field ◽  
Dark Sector ◽  
Negative Mass ◽  
Negative Cosmological Constant ◽  
Viable Model

It is shown that the concept of “negative mass” introduced by Farnes [Astron. Astrophys. 620, A92 (2018)] to describe the dark sector within a unifying theory with the negative cosmological constant contradicts both the essence of the General Relativity (GR) and the available observational data. A viable model with modified weak-field GR is mentioned.

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