  The present work investigates the interrelation between the validity (or
violation) of the cosmic no-hair conjecture and the existence (or
non-existence) of wormholes, both in Einstein's Gravity and in modified gravity
theories. It is found that the existence of wormholes implies a violation of
the cosmic no-hair conjecture, and the validity of the cosmic no-hair
conjecture implies the non-existence of wormholes but not the reverse way both
in Einstein's Gravity and in modified gravity theories. We will also re-visit
the gravitational entropy predictions of the wormhole and show how they are
connected.
