Effectively nonlocal metric-affine gravity. / Golovnev, Alexey; Koivisto, Tomi; Sandstad, Marit.
In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 93, 2016, p. 064081.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Effectively nonlocal metric-affine gravity
AU - Golovnev, Alexey
AU - Koivisto, Tomi
AU - Sandstad, Marit
PY - 2016
Y1 - 2016
N2 - In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric, and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with nonsingular and cosmologically interesting properties may be recovered. Relations between different formulations are analyzed at both perturbative and nonperturbative levels, taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.
AB - In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric, and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with nonsingular and cosmologically interesting properties may be recovered. Relations between different formulations are analyzed at both perturbative and nonperturbative levels, taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.
U2 - 10.1103/PhysRevD.93.064081
DO - 10.1103/PhysRevD.93.064081
M3 - статья
VL - 93
SP - 064081
JO - Physical review D
JF - Physical review D
SN - 2470-0010
ER -
ID: 7559282