Theoretical High Energy Seminar – University of Copenhagen

Discovery Center > Discovery calendar > Calendar 2011 > Theoretical High Energ...

Theoretical High Energy Seminar

Speaker: Sen Zhang, KEK, Tsukuba

Title: Stochastic Approach to Unruh Effect

Abstract: Due to the Unruh effect, an uniformly accelerated particle
sees the Minkowski vacuum as thermally excited. It is expected that
the accelerated particle moves stochastically due to an interaction
with the thermal bath. This interaction should fluctuate the
particle’s transverse momenta like the Brownian motion in a heat bath.
Because of this fluctuating motion, it also has been discussed that
the accelerated charged particle emits extra radiation (the Unruh
radiation) in addition to the classical Larmor radiation, and
experiments are under planning to detect such radiation by using
ultrahigh intensity lasers constructed in near future. There are,
however, counterarguments that the radiation is canceled by an
interference effect between the vacuum fluctuation and the fluctuating
motion. In fact, in the case of an internal detector where the
Heisenberg equation of motion can be solved exactly, there is no
additional radiation after the thermalization is completed. We
analyzed these problems by a stochastic approach. Using a model that
an accelerated charged particle interacts with the scalar field, we
first prove the equipartition theorem of transverse momenta, and then
show that there is a partial cancellation of the radiation. But not
all terms are canceled, and hence there is still a possibility that we
can detect the Unruh radiation by ultrahigh intensity lasers.