Zobrazeno 1 - 10
of 121
pro vyhledávání: '"Sparano, G"'
Publikováno v:
Class.Quant.Grav.28:195014,2011
A solution of the old problem raised by Tolman, Ehrenfest, Podolsky and Wheeler, concerning the lack of attraction of two light pencils "moving parallel", is proposed, considering that the light can be source of nonlinear gravitational waves correspo
Externí odkaz:
http://arxiv.org/abs/1009.3849
Publikováno v:
Differ.Geom.Appl. 17 (2002) 15-35
A formalism (zeta-complex analysis), allowing one to construct global Einstein metrics by matching together local ones described in the papers Phys. Lett. B 513(2001)142-146; Diff. Geom. Appl. 16(2002)95-120, is developed. With this formalism the sin
Externí odkaz:
http://arxiv.org/abs/gr-qc/0301021
Publikováno v:
Differ.Geom.Appl. 16 (2002) 95-120
The solutions of vacuum Einstein's field equations, for the class of Riemannian metrics admitting a non Abelian bidimensional Lie algebra of Killing fields, are explicitly described. They are parametrized either by solutions of a transcendental equat
Externí odkaz:
http://arxiv.org/abs/gr-qc/0301020
Publikováno v:
Phys.Lett. B513 (2001) 142-146
Vacuum gravitational fields invariant for a bidimensional non Abelian Lie algebra of Killing fields, are explicitly described. They are parameterized either by solutions of a transcendental equation (the tortoise equation) or by solutions of a linear
Externí odkaz:
http://arxiv.org/abs/gr-qc/0102112
Autor:
Sparano, G., Vilasi, G.
Publikováno v:
J. Geom. Phys. 653 (2000) 1-15
Geometric structures underlying commutative and non commutative integrable dynamics are analyzed. They lead to a new characterization of noncommutative integrability in terms of spectral properties and of Nijenhuis torsion of an invariant (1,1) tenso
Externí odkaz:
http://arxiv.org/abs/nlin/0011047
Publikováno v:
Mod.Phys.Lett. A13 (1998) 231-238
In a recent paper we pointed out the presence of extra fermionic degrees of freedom in a chiral gauge theory based on Connes Noncommutative Geometry. Here we propose a mechanism which provides a high mass to these mirror states, so that they decouple
Externí odkaz:
http://arxiv.org/abs/hep-th/9704184
Fermion Hilbert Space and Fermion Doubling in the Noncommutative Geometry Approach to Gauge Theories
Publikováno v:
Phys.Rev.D55:6357-6366,1997
In this paper we study the structure of the Hilbert space for the recent noncommutative geometry models of gauge theories. We point out the presence of unphysical degrees of freedom similar to the ones appearing in lattice gauge theories (fermion dou
Externí odkaz:
http://arxiv.org/abs/hep-th/9610035
Publikováno v:
Mod.Phys.Lett. A11 (1996) 2561-2572
The Connes and Lott reformulation of the strong and electroweak model represents a promising application of noncommutative geometry. In this scheme the Higgs field naturally appears in the theory as a particular `gauge boson', connected to the discre
Externí odkaz:
http://arxiv.org/abs/hep-th/9603095
Autor:
Balachandran, A. P., Bimonte, G., Ercolessi, E., Landi, G., Lizzi, F., Sparano, G., Teotonio-Sobrinho, P.
Publikováno v:
J.Geom.Phys. 18 (1996) 163-194
Lattice discretizations of continuous manifolds are common tools used in a variety of physical contexts. Conventional discrete approximations, however, cannot capture all aspects of the original manifold, notably its topology. In this paper we discus
Externí odkaz:
http://arxiv.org/abs/hep-th/9510217
Publikováno v:
J.Geom.Phys. 20 (1996) 318-328
We address the problem of the continuum limit for a system of Hausdorff lattices (namely lattices of isolated points) approximating a topological space $M$. The correct framework is that of projective systems. The projective limit is a universal spac
Externí odkaz:
http://arxiv.org/abs/hep-th/9507147