TY - JOUR
T1 - High energy scattering in gravity and supergravity
AU - B. Giddings, Steven
AU - Schmidt-Sommerfeld, Maximilian
AU - Andersen, Jeppe Rosenkrantz
PY - 2010/11/9
Y1 - 2010/11/9
N2 - 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.
AB - 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.
KW - hep-th
KW - gr-qc
U2 - 10.1103/PhysRevD.82.104022
DO - 10.1103/PhysRevD.82.104022
M3 - Journal article
VL - 82
JO - Phys.Rev.D
JF - Phys.Rev.D
IS - 10
ER -