arXiv subjects

Giuseppe Maiella

Publications and source records attributed to Giuseppe Maiella.

4 recordsLinked to original sources

arXiv2013

Quantization of Black Holes entropy and its cosmological consequences

Starting from a quantization relation for primordial extremal black holes with electric and magnetic charges, it is shown that their entropy is quantized. Furthermore the energy levels spacing for such black holes is derived as a function of the level number $n$, appearing in the quantization relation. Some interesting cosmological consequences are presented for small values of $n$. By producing a mismatch between the mass and the charge the black hole temperature is derived and its behavior investigated. Finally extending the quantum relation to Schwarzschild black holes their temperature is found to be in agreement with the Hawking temperature and a simple interpretation of the microscopic degrees of freedom of the black holes is given.

hep-th↗

arXiv2010

The Cardy-Verlinde equation in a spherical symmetric gravitational collapse

The Cardy-Verlinde formula is analyzed in the contest of the gravitational collapse. Starting from the holographic principle, we show how the equations for a homogeneous and isotropic gravitational collapse describe the formation of the black hole entropy. Some comments on the role of the entangled entropy and the connection with the c-theorem are made.

hep-th↗

arXiv2008

Black Hole in ADS and Quantum Field Theory

I will present a short review of recent achievements in understanding the origin of the statistical properties versus the thermodynamical ones for Anti De Sitter space--time, ADS$_{n+1}$ from the point of view of the "dual" field theory defined on the boundary of ADS$_{n+1}$ conformal invariant, CFT$_n$. We try to convince the audience that the symmetries of Quantum Field Theory at the critical points are, on one side, at the basis of the thermodynamical properties of Black Hole solution, i.e. the Hawking temperature $T_H$ and the entropy $S_H$; on the other side the CFT$_n$ in Euclidean time determines the statistical properties of BH.

hep-th↗

arXiv2005

A Unifying Conformal Field Theory Approach to the Quantum Hall Effect

We review the main results of the effective description of the Quantum Hall fluid for the Jain fillings, nu=m/2pm+1, and the non-standard ones nu=m/pm+2 by a conformal field theory (CFT) in two dimensions. It is stressed the unifying character of the m-reduction procedure to construct appropriate twisted CFT models, called Twisted Models (TM), which by construction reproduce the Quantum Hall topological properties at those fillings. Indeed for the Jain plateaux we find that the different descriptions given in the literature fall into different sectors of the TM for the torus topology. Other interesting aspects are explicitly seen for the m=2 non standard filling nu=1/p+1 (the pairing case) as the merging of non-Abelian statistics or the instability of the TM model (c=2) versus the Moore-Read one (c=3/2). Furthermore by using Boundary CFT techniques the presence of localized impurities and/or dissipation is shown to be closely connected with the twisted sector of the TM, whose presence assures the consistency of the construction and whose role in describing non trivial global properties of 2D quantum condensed matter systems is still under study.

hep-th↗