Informal Pizza Seminar
Chameleon Scalar Fields and Awaiting Surprises
for
Tests of Gravity in Space
Justin Khoury
Columbia University
We present a novel scenario where a scalar field acquires a mass which
depends on the local matter density: the field is massive on Earth, where the
density is high, but is essentially free in the solar system, where the
density is low. All existing tests of gravity are satisfied. We predict that
near-future satellite experiments could measure an effective Newton's
constant in space different than that on Earth, as well as violations of the
Equivalence Principle stronger than currently allowed by laboratory
experiments. We discuss the cosmological evolution with a chameleon field and
show how the chameleon can naturally be the quintessence field driving the
current phase of cosmic acceleration.
Friday, June 4th 2004, 11:30
Ernest Rutherford Physics Building, room 326
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