NUCLEAR PHYSICS B

A non-static quantum inspired spacetime in () gravity: Gravity's rainbow
Rudra P
In this note we explore a non-static spacetime in quantum regime in the background of gravity. The time dependent Vaidya metric which represents the spacetime of a radiating body like star is studied in an energy dependent gravity's rainbow, which is a UV completion of General Relativity. In our quest we have used gravitational collapse as the main tool. The focus is to probe the nature of singularity (black hole or naked singularity) formed out of the collapsing procedure. This is achieved via a geodesic study. For our investigation we have considered two different models of gravity, namely the inflationary Starobinsky's model and the power law model. Our study reveals the fact that naked singularity is as good a possibility as black hole as far as the central singularity is concerned. Via a proper fine tuning of the initial data, we may realize both black hole or naked singularity as the end state of the collapse. Thus this study is extremely important and relevant in the light of the Cosmic Censorship hypothesis. The most important result derived from the study is that gravity's rainbow increases the tendency of formation of naked singularities. We have also deduced the conditions under which the singularity will be a strong or weak curvature singularity. Finally in our quest to know more about the model we have performed a thermodynamical study. Throughout the study we have obtained results which involve deviation from the classical set-up. Such deviations are expected in a quantum evolution and can be attributed to the quantum fluctuations that our model suffers from. It is expected that this study will enhance our knowledge about quantization of gravity and subsequently about the illusive theory of quantum gravity.
Asymptotic correlation functions and FFLO signature for the one-dimensional attractive spin-1/2 Fermi gas
Lee JY and Guan XW
We investigate the long distance asymptotics of various correlation functions for the one-dimensional spin-1/2 Fermi gas with attractive interactions using the dressed charge formalism. In the spin polarized phase, these correlation functions exhibit spatial oscillations with a power-law decay whereby their critical exponents are found through conformal field theory. We show that spatial oscillations of the leading terms in the pair correlation function and the spin correlation function solely depend on [Formula: see text] and [Formula: see text], respectively. Here [Formula: see text] denotes the mismatch between the Fermi surfaces of spin-up and spin-down fermions. Such spatial modulations are characteristics of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. Our key observation is that backscattering among the Fermi points of bound pairs and unpaired fermions results in a one-dimensional analog of the FFLO state and displays a microscopic origin of the FFLO nature. Furthermore, we show that the pair correlation function in momentum space has a peak at the point of mismatch between both Fermi surfaces [Formula: see text], which has recently been observed in numerous numerical studies.
The [Formula: see text] massive operator matrix elements of [Formula: see text] for the structure function [Formula: see text] and transversity
Ablinger J, Blümlein J, Klein S, Schneider C and Wißbrock F
The contributions [Formula: see text] to the [Formula: see text] massive operator matrix elements describing the heavy flavor Wilson coefficients in the limit [Formula: see text] are computed for the structure function [Formula: see text] and transversity for general values of the Mellin variable . Here, for two matrix elements, [Formula: see text] and [Formula: see text], the complete result is obtained. A first independent computation of the contributions to the 3-loop anomalous dimensions [Formula: see text], [Formula: see text], and [Formula: see text] is given. In the computation advanced summation technologies for nested sums over products of hypergeometric terms with harmonic sums have been used. For intermediary results generalized harmonic sums occur, while the final results can be expressed by nested harmonic sums only.