The near-horizon properties of a black hole are studied within an algebraic framework, using a scalar field as a simple probe to analyze the geometry. The operator H governing the near-horizon dynamics of the scalar field contains an inverse square interaction term. It is shown that the operators appearing in the corresponding algebraic description belong to the representation space of the Vira...

The quantum entropy of the Kerr black hole arising from gravitational perturbation is investigated by using Null tetrad and ’t Hooft brick-wall model. It is shown that the effect of the graviton’s spin to the entropy is dependent of the square of the spin and the angular momentum per unit mass of the black hole, and contribution of logarithm term to the entropy will be positive, zero, and negat...

We consider a correlated wavefunction including particle-hole pairing at half a reciprocal lattice vector for itinerant electrons hopping on a square lattice in two dimensions and subject both to on-site and nearest-neighbor repulsion. We find, within mean field theory, that in a suitable range of parameters there is a tendency toward a novel form of ordering characterized by discrete symmetry ...

Neutralino dark matter may be incompatible with current cold dark matter models with cuspy dark halos, because excessive synchrotron radiation may originate from neutralino annihilations close to the black hole at the galactic center. We report results obtained in [1], to which we refer for further details. The composition of dark matter is one of the major issues in cosmology. A popular candid...

Medium Field Equation (MFE) multivariate public key cryptosystems were broken by High Order Linearization Equation (HOLE) attack. In order to avoid HOLE attack, we proposed an improvement of MFE, Cubic MFE public key encryption scheme. In our construction, multiplications of three second order matrices were used to get a set of cubic polynomials in the central map. Through theoretical analysis ...

We propose a scenario in which massive stars form in a self-gravitating gaseous disc around a supermassive black hole. We analyze the dynamics of a disc forming around a supermassive black hole, in which the angular momentum is transported by turbulence induced by the disc’s self-gravity. We find that once the surface density of the disc exceeds a critical value, the disc fragments into dense c...

We analyze the observed distribution of Eddington ratios (L/LEdd) as a function of supermassive black hole mass for a large sample of nearby galaxies drawn from the Sloan Digital Sky Survey. We demonstrate that there are two distinct regimes of black hole growth in nearby galaxies. The first is associated with galaxies with significant star formation (M∗/SFR ∼ a Hubble time) in their central ki...