Non-equilibrium fluctuation-dissipation relation from holography

We derive a non-equilibrium fluctuation-dissipation relation for bosonic correlation functions from holography in the classical gravity approximation at strong coupling. This generalizes the familiar thermal fluctuation-dissipation relation in absence of external sources. This also holds universally for any non-equilibrium state which can be obtained from a stable thermal equilibrium state in perturbative derivative (hydrodynamic) and amplitude (non-hydrodynamic) expansions. Therefore, this can provide a strong experimental test for the applicability of the holographic framework. We discuss how it can be tested in heavy ion collisions. We also make a conjecture regarding multi-point holographic non-equilibrium Green's functions.Comment: 40 pages, 3 figures, revtex; a small change in the Introduction for clarity and a reference added, accepted in PR

Lessons from charm dynamics

We shall proceed to discuss the significance of charm dynamics in an era when the Standard Model is well established in its degrees of freedom but little understood in quite a few of its different parts. The study of decays and asymmetries in the decays of mesons with charm quantum numbers provide us possible insights into the yet uncharted dynamics of the Standard Model at the GeV scale. We will discuss some interesting channels with hadrons and/or leptons in the final state, the shortcomings of theoretical structures currently advocated and future experimental prospects.Comment: Proceedings of XII IFAE, Cittadella Universitaria di Monserrato, Cagliari. 3rd - 5th April 2013. 5 page

Phenomenological characterisation of semi-holographic non-Fermi liquids

We analyse some phenomenological implications of the most general semi-holographic models for non-Fermi liquids that have emerged with inputs from the holographic correspondence. We find generalizations of Landau-Silin equations with few parameters governing thermodynamics, low energy response and collective excitations. We show that even when there is a Fermi surface with well-defined quasi-particle excitations, the collective excitations can behave very differently from Landau's theory.Comment: 5+5 pages, 3 figures, expanded supplementary material, published versio

Semiholography for heavy ion collisions

The formation of QGP in heavy ion collisions gives us a great opportunity for learning about nonperturbative dynamics of QCD. Semiholography provides a new consistent framework to combine perturbative and non-perturbative effects in a coherent way and can be applied to obtain an effective description for heavy ion collisions. In particular, it allows us to include nonperturbative effects in existing glasma effective theory and QCD kinetic theory for the weakly coupled saturated degrees of freedom liberated by the collisions in the initial stages in a consistent manner. We argue why the full framework should be able to confront experiments with only a few phenomenological parameters and present feasibility tests for the necessary numerical computations. Furthermore, we discuss that semiholography leads to a new description of collective flow in the form of a generalised non-Newtonian fluid. We discuss some open questions which we hope to answer in the near future.Comment: 12 pages; 3 figures; Proceedings of Confinement XII @ Thessaloniki, Greece -- August 28 to September 4, 201

A New Guess-and-Determine Attack on the A5/1 Stream Cipher

In Europe and North America, the most widely used stream cipher to ensure privacy and confidentiality of conversations in GSM mobile phones is the A5/1. In this paper, we present a new attack on the A5/1 stream cipher with an average time complexity of 2^(48.5), which is much less than the brute-force attack with a complexity of 2^(64). The attack has a 100% success rate and requires about 5.65GB storage. We provide a detailed description of our new attack along with its implementation and results.Comment: 14 pages, 4 figures, 3 table