Wormholes, Broken Clocks, and Hiring Fraud
by Jim ISENBERG (U.Oregon)
Abstract:
General relativistic spacetime models of the universe do not generally
come equipped with a natural choice of time. We need to make a choice
of cosmological clock. The most popular choice of clock has been that
which is based on a foliation of spacetime by constant mean curvature
("CMC") slices. It has long been believed that most cosmological
spacetimes which satisfy Einstein's gravitational field equations admit
such a choice of time. Chrusciel, Pollack and I have now shown that
this is not the case. Using our recently developed results which
describe how to glue together solutions of Einstein's equations, we
show that there is a class of cosmological spacetimes which do not
admit CMC slicing. In this talk, after providing a bit of background in
general relativity, we discuss the gluing method and show how we use it
prove the existence of these spacetimes with no CMC slices. We also
discuss some of the other applications of gluing, including the
construction of spacetimes with lots of wormholes and with lots of
black holes.