arXiv subjects
Publications and source records attributed to Yi Pang.
Recently, a state of the art experiment shows evidence for Lorentz violation in the gravitational sector. To explain this experiment, we investigate a spontaneous Lorentz violation scenario with a generalized scalar field. We find that when the scalar field is nonminimally coupled to gravity, the Lorentz violation induces a deformation in the Newtonian potential along the direction of Lorentz violation.
In this short note, we reduce the N=6, U(N)xU(N) Chern-Simons gauge theories to N=8, U(N) Yang-Mills gauge theories. This process corresponds to recovering the world-volume theory of N D2-branes from that of N M2-branes in an intermediate energy range. The supersymmetries are enhanced because in this limit the branes localize far away from the orbifold singularity. Our main scheme is exactly in accordance with Mukhi and Papageorgakis's earlier work, although the Higgs mechanism becomes trickier in the present case. We also speculate on applying the scheme to a large class of new Bagger-Lambert models more generally.
We propose a model in which an energy-dependent time delay of a photon originates from space-time non-commutativity, the time delay is due to a noncommutative coupling between dilaton and photon. We predict that in our model, high energy photons with different momenta can either be delayed or superluminal, this may be related to a possible time delay reported by the Fermi LAT and Fermi GBM Collaborations.
In this paper, we calculate the transverse momentum diffusion coefficient kappa_T of heavy quark and gluon penetration length in the deconfinement phase of Sakai-Sugimoto model, which is known as a holographic dual of large N_c QCD. We find that for the heavy quark moving through the thermal plasma with a constant velocity v<1, the transverse momentum diffusion coefficient kappa_T is proportional to lamda*gamma^{1/3}*T^4/T_d, and the gluon penetration length delta x is proportional to E^{2/5}. These results are different from those calculated in N=4 super-Yang-Mills theory, where kappa_T is proportional to lambda*gamma^{1/2}*T^3 and delta x is proportional to E^{1/3}, respectively. In the high energy limit, the difference between the two pairs of results should be evident, so we expect that the future LHC experiments can tell us which model is more closely related to the realistic strongly coupled QCD at finite temperature.