Quantum amplification effect in a horizon fluctuations

The appearance of a few unevenly- spaced bright flashes of light on top of Hawking radiation is the sign of the amplification effect in black hole horizon fluctuations. Previous studies on this problem suffer from the lack of considering all emitted photons in the theoretical spectroscopy of these fluctuations. In this paper, we include all of the physical transition weights and present a consistent intensity formula. This modifies a black hole radiation pattern.Comment: 6 pages, 2 figure

Fluctuations of the partial filling factors in competitive RSA from binary mixtures

Competitive random sequential adsorption on a line from a binary mix of incident particles is studied using both an analytic recursive approach and Monte Carlo simulations. We find a strong correlation between the small and the large particle distributions so that while both partial contributions to the fill factor fluctuate widely, the variance of the total fill factor remains relatively small. The variances of partial contributions themselves are quite different between the smaller and the larger particles, with the larger particle distribution being more correlated. The disparity in fluctuations of partial fill factors increases with the particle size ratio. The additional variance in the partial contribution of smaller particle originates from the fluctuations in the size of gaps between larger particles. We discuss the implications of our results to semiconductor high-energy gamma detectors where the detector energy resolution is controlled by correlations in the cascade energy branching process.Comment: 19 pages, 8 figure

Spherically symmetric spacetimes in massive gravity

We explore spherically symmetric stationary solutions, generated by ``stars'' with regular interiors, in purely massive gravity. We reexamine the claim that the resummation of non-linear effects can cure, in a domain near the source, the discontinuity exhibited by the linearized theory as the mass m of the graviton tends to zero. First, we find analytical difficulties with this claim, which appears not to be robust under slight changes in the form of the mass term. Second, by numerically exploring the inward continuation of the class of asymptotically flat solutions, we find that, when m is ``small'', they all end up in a singularity at a finite radius, well outside the source, instead of joining some conjectured ``continuous'' solution near the source. We reopen, however, the possibility of reconciling massive gravity with phenomenology by exhibiting a special class of solutions, with ``spontaneous symmetry breaking'' features, which are close, near the source, to general relativistic solutions and asymptote, for large radii, a de Sitter solution of curvature ~m^2.Comment: 57 pages, references addde

QCD-Thermodynamics using 5-dim Gravity

We calculate the critical temperature and free energy of the gluon plasma using the dilaton potential arXiv:0911.0627[hep-ph] in the gravity theory of AdS/QCD. The finite temperature observables are calculated in two ways: first, from the Page-Hawking computation of the free energy, and secondly using the Bekenstein-Hawking proportionality of the entropy with the area of the horizon. Renormalization is well defined, because the T=0 theory has asymptotic freedom. We further investigate the change of the critical temperature with the number of flavours induced by the change of the running coupling constant in the quenched theory. The finite temperature behaviour of the speed of sound, spatial string tension and vacuum expectation value of the Polyakov loop follow from the corresponding string theory in AdS_5.Comment: 38 pages, 12 figure

Dual Response Models for the Fractional Quantum Hall Effect

It is shown that the Jain mapping between states of integer and fractional quantum Hall systems can be described dynamically as a perturbative renormalization of an effective Chern-Simons field theory. The effects of mirror duality symmetries of toroidally compactified string theory on this system are studied and it is shown that, when the gauge group is compact, the mirror map has the same effect as the Jain map. The extrinsic ingredients of the Jain construction appear naturally as topologically non-trivial field configurations of the compact gauge theory giving a dynamical origin for the Jain hierarchy of fractional quantum Hall states.Comment: 8 pages LaTe

London penetration depth and strong pair-breaking in iron-based superconductors

The low temperature variation of the London penetration depth for a number of iron-pnictide and iron-chalcogenide superconductors is nearly quadratic, $\Delta \lambda(T) = \beta T^n$ with $n\approx 2$. The coefficient in this dependence shows a robust scaling, $\beta \propto 1/T_c^3$ across different families of these materials. We associate the scaling with a strong pair-breaking. The same mechanism have recently been suggested to explain the scalings of the specific heat jump, $\Delta C \propto T_c^3$, and of the slopes of the upper critical field, $dH_{c2}/dT\propto T_c$ in these materials. This suggests that thermodynamic and electromagnetic properties of the iron-based superconductors can be described within a strong pair-breaking scenario

Nature of 45 degree vortex lattice reorientation in tetragonal superconductors

The transformation of the vortex lattice in a tetragonal superconductor which consists of its 45 degree reorientation relative to the crystal axes is studied using the nonlocal London model. It is shown that the reorientation occurs as two successive second order (continuous) phase transitions. The transition magnetic fields are calculated for a range of parameters relevant for borocarbide superconductors in which the reorientation has been observed

Elasticity-driven interaction between vortices in type-II superconductors

The contribution to the vortex lattice energy which is due to the vortex-induced strains is calculated covering all the magnetic field range which defines the vortex state. This contribution is compared with previously reported ones what shows that, in the most part of the vortex state, it has been notably underestimated until now. The reason of such underestimation is the assumption that only the vortex cores induce strains. In contrast to what is generally assumed, both core and non-core regions are important sources of strains in high-$\kappa$ superconductors.Comment: 10 pages, 1 figure, revtex