High energy scattering in gravity and supergravity
arXiv:1005.5408 · doi:10.1103/PhysRevD.82.104022
Abstract
We investigate features of perturbative gravity and supergravity by studying scattering in the ultraplanckian limit, and sharpen arguments that the dynamics is governed by long-distance physics. A simple example capturing aspects of the eikonal resummation suggests why short distance phenomena and in particular divergences or nonrenormalizability do not necessarily play a central role in this regime. A more profound problem is apparently unitarity. These considerations can be illustrated by showing that known gravity and supergravity amplitudes have the same long-distance behavior, despite the extra light states of supergravity, and this serves as an important check on long-range dynamics in a context where perturbative amplitudes are finite. We also argue that these considerations have other important implications: they obstruct probing the conjectured phenomenon of asymptotic safety through a physical scattering process, and ultraplanckian scattering exhibiting Regge behavior. These arguments sharpen the need to find a nonperturbative completion of gravity with mechanisms which restore unitarity in the strong gravity regime.
26 pages, 7 figures, harvmac. v2: added refs; clarified Regge discussion
References in corpus (12)
- Semiclassical relations and IR effects in de Sitter and slow-roll space-times
- Is N = 8 Supergravity Ultraviolet Finite?
- Black hole information, unitarity, and nonlocality
- Locality in quantum gravity and string theory
- Gravitational effects in ultrahigh-energy string scattering
- A Critique of Pure String Theory: Heterodox Opinions of Diverse Dimensions
- (Non)perturbative gravity, nonlocality, and nice slices
- High-energy gravitational scattering and black hole resonances
- Quantization in black hole backgrounds
- High-energy black hole production
- Relational observables in 2d quantum gravity
- Reggeization of N=8 Supergravity and N=4 Yang--Mills Theory