Cosmological Supergravity Research Articles

Addendum: A note on spin two fields in curved backgrounds (2007 Class. Quantum Grav. 24 1683)

Abstract Some time ago, we showed that a weak (linear) massless spin two wave could only propagate on a Ricci-flat or Ricci-constant background: it must necessarily be a perturbation of general relativity. This was just the continuation of the higher spin chain: massless s = 3/2 also required Ricci-flatness (which is the basis of supergravity) while s > 2 needs Riemann flatness. This note, entitled ‘higher spin m ≠ 0 excitations on curved backgrounds and cosmological supergravity’, re-analyzes the problem in a perhaps more physical way: by considering massless and—only apparently—massive small excitations and showing how their parameters relate to the cosmological constant. We will thus prove, in a simple physical way, the necessity, as well as the sufficiency, of the known supergravity results.

(Dis)continuities of massless limits in spin-3/2-mediated interactions and cosmological supergravity

We extend to its spin-3/2 supersymmetric partner the very recent demonstration that the massless limit of massive spin-2 exchange amplitudes can be made continuous in background AdS spaces, in contrast to the known flat space discontinuities for both systems. In an AdS background, unlike spin-2 where the limit m→0 is the massless one, spin-3/2 “masslessness” requires m→ −Λ/3 , the supergravity value tuning the mass and cosmological constant that uniquely provides gauge invariance and two helicities. We find that continuity of the spin-3/2-mediated exchange amplitude can be regained in two “massless” limits m→0 and m→ −Λ/3 ; only the latter corresponds to cosmological supergravity.

Cosmological supergravity from a massive superparticle and super-cosmological black holes

We describe in superspace a classical theory of two-dimensional (1, 1) dilaton supergravity with a cosmological constant, both with and without coupling to a massive superparticle. We give general exact non-trivial superspace solutions for the compensator superfield that describes the supergravity in both cases. We then use these compensator solutions to construct models of two-dimensional supersymmetric cosmological black holes.

Super black hole from cosmological supergravity with a massive superparticle

We describe in superspace a classical theory of two dimensional (1,1) cosmological dilaton supergravity coupled to a massive superparticle. We give an exact non-trivial superspace solution for the compensator superfield that describes the supergravity, and then use this solution to construct a model of a two-dimensional supersymmetric black hole.