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Schlagwörter:
General Relativity and Quantum Cosmology, gr-qc,High Energy Physics - Theory, hep-th
Zusammenfassung:
The gravitational interaction is expected to be modified for very short
distances. This is particularly important in situations in which the curvature
of spacetime is large in general, such as close to the initial cosmological
singularity. The gravitational dynamics is then captured by the higher
curvature terms in the action, making it difficult to reliably extrapolate any
prediction of general relativity. In this note we review pure Lovelock
equations for Kasner-type metrics. These equations correspond to a single $N$th
order Lovelock term in the action in $d=2N+1,\,2N+2$ dimensions, and they
capture the relevant gravitational dynamics when aproaching the big-bang
singularity within the Lovelock family of theories. These are classified in
several isotropy types. Some of these families correspond to degenerate classes
of solutions, such that their dynamics is not completely determined by the
equations of pure Lovelock gravity. Instead, these Kasner solutions become
sensitive to the subleading terms in the Lovelock series.