  We extend a recent de Sitter holographic proposal and entanglement entropy
prescription to generic closed FRW cosmologies in arbitrary dimensions, and
propose that for large classes of bouncing and Big Bang/Big Crunch cosmologies,
the full spacetime can be encoded holographically on two holographic screens,
associated to two antipodal observers. In the expanding phase, the two screens
lie at the apparent horizons. In the contracting phase, there is an infinite
number of possible trajectories of the holographic screens, which can be
grouped in equivalence classes. In each class the effective holographic theory
can be derived from a pair of ``parent'' screens on the apparent horizons. A
number of cases including moduli-dominated cosmologies escape our discussion,
and it is expected that two antipodal observers and their associated screens do
not suffice to reconstruct these cosmologies. The leading contributions to the
entanglement entropy between the screens arise from a minimal extremal trapped
or anti-trapped surface lying in the region between them. This picture entails
a time-dependent realization of the ER=EPR conjecture, where an effective
geometrical bridge connecting the screens via the minimal extremal surface
emerges from entanglement. For the Big Crunch contracting cases, the screens
disentangle and the geometrical bridge closes off when the minimal extremal
trapped sphere hits the Big Crunch singularity at a finite time before the
collapse of the Universe. Semiclassical, thermal corrections are incorporated
in the cases of radiation-dominated cosmologies.

High Energy Physics - Theory