We investigate N = 2 super-Yang-Mills theory on a three sphere in the presence of an isospin chemical potential at strong coupling using the AdS/CFT correspondence. This system exhibits an instability for sufficiently large values of the chemical potential. In contrast to other related models, the first excitation to condense is not a vector meson but rather a scalar charged under the global SO(4) symmetry group. Furthermore, the spectrum of fluctuations exhibits an interesting cross-over behaviour as a function of the dimensionless temperature. We construct the new ground state of the non-linear theory.arXiv:1210.6188v1 [hep-th]

Abstract:We study the effect of a magnetic field on N = 2 super-Yang-Mills on S 3 at strong coupling using the gauge/gravity correspondence. As in previous work that dealt with the theory in infinite volume, we find that increasing the magnetic field pushes the system into the confined phase. However, we in addition also find that, within the class of configurations with the same symmetry as those which describe the ground state at vanishing magnetic field, a mass gap appears in the spectrum. This suggests the existence of a new phase with so far unexplored symmetry structure. We provide suggestions for the physical properties of this phase.

We study the Rényi holographic dark energy (RHDE) model by using the future and the particle horizons as the infrared (IR) cut-off. With the initial condition from the literature, most of the cosmological parameters are computed. Some of the results agree with the observation that the present universe is in accelerating expansion and in a phantom phase.