5,694 research outputs found
Direct solution of the hard pomeron problem for arbitrary conformal weight
A new method is applied to solve the Baxter equation for the one dimensional
system of noncompact spins. Dynamics of such an ensemble is equivalent to that
of a set of reggeized gluons exchanged in the high energy limit of QCD
amplitudes. The technique offers more insight into the old calculation of the
intercept of hard Pomeron, and provides new results in the odderon channel.Comment: Contribution to the ICHEP96 Conference, July 1996, Warsaw, Poland.
LaTeX, 4 pages, 3 epsf figures, includes modified stwol.sty file. Some
references were revise
Solution of the Odderon Problem
The intercept of the odderon trajectory is derived, by finding the spectrum
of the second integral of motion of the three reggeon system in high energy
QCD. When combined with earlier solution of the appropriate Baxter equation,
this leads to the determination of the low lying states of that system. In
particular, the energy of the lowest state gives the intercept of the odderon
alpha_O(0)=1-0.2472 alpha_s N_c/pi.Comment: 11 pages, 2 Postscript figure
The characteristics of thermalization of boost-invariant plasma from holography
We report on the approach towards the hydrodynamic regime of boost-invariant
N=4 super Yang-Mills plasma at strong coupling starting from various
far-from-equilibrium states at tau=0. The results are obtained through
numerical solution of Einstein's equations for the dual geometries, as
described in detail in the companion article arXiv:1203.0755. Despite the very
rich far-from-equilibrium evolution, we find surprising regularities in the
form of clear correlations between initial entropy and total produced entropy,
as well as between initial entropy and the temperature at thermalization,
understood as the transition to a hydrodynamic description. For 29 different
initial conditions that we consider, hydrodynamics turns out to be definitely
applicable for proper times larger than 0.7 in units of inverse temperature at
thermalization. We observe a sizable anisotropy in the energy-momentum tensor
at thermalization, which is nevertheless entirely due to hydrodynamic effects.
This suggests that effective thermalization in heavy ion collisions may occur
significantly earlier than true thermalization.Comment: 4 pages, 5 figures; see also the companion article arXiv:1203.0755;
v2: figure corrected (fixes problem with Acrobat); v3: various clarifications
and additional data points added; v4: typo fixed, publishe
Non-lattice simulation for supersymmetric gauge theories in one dimension
Lattice simulation of supersymmetric gauge theories is not straightforward.
In some cases the lack of manifest supersymmetry just necessitates cumbersome
fine-tuning, but in the worse cases the chiral and/or Majorana nature of
fermions makes it difficult to even formulate an appropriate lattice theory. We
propose to circumvent all these problems inherent in the lattice approach by
adopting a non-lattice approach in the case of one-dimensional supersymmetric
gauge theories, which are important in the string/M theory context.Comment: REVTeX4, 4 pages, 3 figure
Asymptotic perfect fluid dynamics as a consequence of AdS/CFT
We study the dynamics of strongly interacting gauge-theory matter (modelling
quark-gluon plasma) in a boost-invariant setting using the AdS/CFT
correspondence. Using Fefferman-Graham coordinates and with the help of
holographic renormalization, we show that perfect fluid hydrodynamics emerges
at large times as the unique nonsingular asymptotic solution of the nonlinear
Einstein equations in the bulk. The gravity dual can be interpreted as a black
hole moving off in the fifth dimension. Asymptotic solutions different from
perfect fluid behaviour can be ruled out by the appearance of curvature
singularities in the dual bulk geometry. Subasymptotic deviations from perfect
fluid behaviour remain possible within the same framework.Comment: 19 pages, 1 figure; v2: free streaming example changed to s=1;
conclusions unchange
Supergravitons from one loop perturbative N=4 SYM
We determine the partition function of 1/16 BPS operators in N=4 SYM at weak
coupling at the one-loop level in the planar limit. This partition function is
significantly different from the one computed at zero coupling. We find that it
coincides precisely with the partition function of a gas of 1/16 BPS
`supergravitons' in AdS_5xS^5.Comment: 22 pages; v2: references adde
Spectral Curves of Non-Hermitean Hamiltonians
Recent analytical and numerical work have shown that the spectrum of the
random non-hermitean Hamiltonian on a ring which models the physics of vortex
line pinning in superconductors is one dimensional. In the maximally
non-hermitean limit, we give a simple "one-line" proof of this feature. We then
study the spectral curves for various distributions of the random site
energies. We find that a critical transition occurs when the average of the
logarithm of the random site energy squared vanishes. For a large class of
probability distributions of the site energies, we find that as the randomness
increases the energy at which the localization-delocalization transition occurs
increases, reaches a maximum, and then decreases. The Cauchy distribution
studied previously in the literature does not have this generic behavior. We
determine the critical value of the randomness at which "wings" first appear in
the energy spectrum. For distributions, such as Cauchy, with infinitely long
tails, we show that this critical value is infinitesimally above zero. We
determine the density of eigenvalues on the wings for any probability
distribution. We show that the localization length on the wings diverges
linearly as the energy approaches the energy at which the
localization-delocalization transition occurs. These results are all obtained
in the maximally non-hermitean limit but for a generic class of probability
distributions of the random site energies.Comment: 36 pages, 5 figures (.ps), LaTe
An apparatus for the electrodynamic containment of charged macroparticles
The dynamic moition of the ions contained in the trapped (199)Hg+ frequency standard contributes to the stability of the standard. In order to study these dynamics, a macroscopic analog of the (199)Hg+ trap is constructed. Containment of micron-sized particles in this trap allows direct visual observation of the particles' motion. Influenced by the confining fields and their own Coulomb repulsion, the particles can form stable arrays
- …