3,187 research outputs found
Gravity Dual Corrections to the Heavy Quark Potential at Finite-Temperature
We apply gauge/gravity duality to compute corrections to the heavy
quark potentials of a quark--anti-quark pair () and of a quark--quark
pair () immersed into the strongly coupled N = 4 SYM plasma. On the gravity
side these corrections come from the exchanges of supergravity modes between
two string worldsheets stretching from the UV boundary of AdS space to the
black hole horizon in the bulk and smeared over . We find that the
contributions to the potential coming from the exchanges of all of
the relevant modes (such as dilaton, massive scalar, 2-form field, and
graviton) are all attractive, leading to an attractive net potential.
We show that at large separations and/or high-temperature the potential
is of Yukawa-type, dominated by the graviton exchange, in agreement with
earlier findings. On the other hand, at small- the potential
scales as . In the case of potential the 2-form
contribution changes sign and becomes repulsive: however, the net
potential remains attractive. At large- it is dominated by the graviton
exchange, while at small- the potential becomes Coulomb-like.Comment: 45 pages, 14 figures; v2: refs added, typos correcte
Self-amplified Emission of Cherenkov Radiation from a Relativistic Particle Inside Layered Dielectric-filled Waveguide
It is shown that in some special cases the Cherenkov radiation from a charged
particle moving along the axis of cylindrical waveguide filled with a
semi-infinite material consisting of dielectric plates alternated with vacuum
gaps is many times stronger than that in the waveguide filled with
semi-infinite solid dielectric without vacuum gaps.Comment: 1 page, abstract submitted to 4th International Conference
"Channeling 2010", Ferrara, Italy, October 3-8, 201
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