Holographic Nucleons in the Nuclear Medium

We investigate the nucleon's rest mass and dispersion relation in the nuclear medium which is holographically described by the thermal charged AdS geometry. On this background, the chiral condensate plays an important role to determine the nucleon's mass in both the vacuum and the nuclear medium. It also significantly modifies the nucleon's dispersion relation. The nucleon's mass in the high density regime increases with density as expected, while in the low density regime it slightly decreases. We further study the splitting of the nucleon's masses caused by the isospin interaction with the nuclear medium.Comment: 15 pages, 6 figure

Thermodynamics of Three-dimensional Black Holes via Charged Particle Absorption

We have shown that changes occur in a (2+1)-dimensional charged black hole by adding a charged probe. The particle increases the entropy of the black hole and guarantees the second law of thermodynamics. The first law of thermodynamics is derived from the change in the black hole mass. Using the particle absorption, we test the extremal black hole and find out that the mass of the extremal black hole increases more than the electric charge. Therefore, the outer horizon of the black hole still exists. However, the extremal condition becomes non-extremal.Comment: 6 page

Geodesic Properties and Orbits in 5-dimensional Hypercylindrical Spacetime

We investigate the geodesic motions of a massive particle and light ray in the hyperplane orthogonal to the symmetry axis in the 5-dimensional hypercylindrical spacetime. The class of the solutions depends on one constant a which is the ratio of string mass density and tension. There exist unstable orbits in null geodesic only in some range of a. The innermost stable circular orbits in timelike geodesic also exist only in a certain range of the parameter a. The capture cross section and the deflection angle of light ray are also computed.Comment: 17 pages, 10 figures, 4 tables, minor corrected and reference adde