Zobrazeno 1 - 10
of 305
pro vyhledávání: '"De Ritis R"'
Publikováno v:
Mon.Not.Roy.Astron.Soc. 357 (2005) 773-782
We evaluate the effect of small scale inhomogeneities on large scale observations within the statistics of gravitationally lensed quasars. At this aim, we consider a cosmological model whose large scale properties (dynamics, matter distribution) are
Externí odkaz:
http://arxiv.org/abs/astro-ph/0501509
Publikováno v:
Astron.Astrophys. 411 (2003) 33-40
We discuss the general and approximate angular diameter distance in the Friedman-Robertson-Walker cosmological models with nonzero cosmological constant. We modify the equation for the angular diameter distance by taking into account the fact that lo
Externí odkaz:
http://arxiv.org/abs/astro-ph/0310830
Autor:
Novati, S. Calchi, Iovane, G., Marino, A. A., Auriere, M., Baillon, P., Bouquet, A., Bozza, V., Capaccioli, M., Capozziello, S., Cardone, V., Covone, G., De Paolis, F., de Ritis, R., Giraud-Heraud, Y., Gould, A., Ingrosso, G., Jetzer, Ph., Kaplan, J., Lambiase, G., Du, Y. Le, Mancini, L., Piedipalumbo, E., Re, V., Roncadelli, M., Rubano, C., Scarpetta, G., Scudellaro, P., Sereno, M., Strafella, F.
Publikováno v:
Astron.Astrophys. 381 (2002) 848-861
We present the first results of the analysis of data collected during the 1998-99 observational campaign at the 1.3 meter McGraw-Hill Telescope, towards the Andromeda galaxy (M31), aimed to the detection of gravitational microlensing effects as a pro
Externí odkaz:
http://arxiv.org/abs/astro-ph/0110706
Publikováno v:
Mon.Not.Roy.Astron.Soc. 327 (2001) 517
We investigate the properties of cosmological distances in locally inhomogeneous universes with pressureless matter and dark energy (quintessence), with constant equation of state. We give exact solutions for angular diameter distances in theempty be
Externí odkaz:
http://arxiv.org/abs/astro-ph/0102486
Autor:
de Ritis, R., Marino, A. A.
Publikováno v:
Phys.Rev.D64:083509,2001
In this paper we present exactly solved extended quintessence models; furthermore, through a dynamical effective Q-cosmological "constant", we recover some of the L decaying cases found in the literature. Finally we introduce a sort of complementarit
Externí odkaz:
http://arxiv.org/abs/astro-ph/0007128
We derive and solve exactly the Dyer-Roeder equation in a Friedman-Robertson-Walker cosmological model with non zero cosmological constant. To take into account non homogeneous distribution of matter we use the phenomenological clumpiness parameter.
Externí odkaz:
http://arxiv.org/abs/astro-ph/0004376
Publikováno v:
Int.J.Mod.Phys.D10:921-926,2001
We join quintessence cosmological scenarios with the duality simmetry existing in string dilaton cosmologies. Actually, we consider the tracker potential type $V = V_0/{\phi}^{\alpha}$ and show that duality is only established if $\alpha = - 2$.
Externí odkaz:
http://arxiv.org/abs/hep-th/9907207
Publikováno v:
Phys.Rev.D62:043506,2000
We extend the concept of quintessence to a flat nonminimally coupled scalar - tensor theories of gravity. By means of Noether's symmetries for the cosmological pointlike Lagrangian L, it is possible to exhibit exact solutions for a class of models de
Externí odkaz:
http://arxiv.org/abs/hep-th/9907198
We investigate the dark halo lens mass function (MF) for a wide class of spheroidal non singular isothermal models comparing observed and observable microlensing quantities for MACHO observations towards LMC and taking into account the detection effi
Externí odkaz:
http://arxiv.org/abs/astro-ph/9907160
Autor:
Collaboration, SLOTT-AGAPE, Bozza, V., Novati, S. Calchi, Capaccioli, M., Capozziello, S., Cardone, V., Covone, G., De Paolis, F., de Ritis, R., Ingrosso, G., Iovane, G., Lambiase, G., Marino, A. A., Marmo, G., Musella, I., Piedipalumbo, E., Pezzuto, S., Roncadelli, M., Rubano, C., Scarpetta, G., Scudellaro, P., Strafella, F.
Publikováno v:
Mem.Soc.Ast.It.71:1113-1116,2001
SLOTT-AGAPE (Systematic Lensing Observation at Toppo Telescope - Andromeda Gravitational Amplification Pixel Lensing Experiment) is a new collaboration project among international partners from England, France, Germany, Italy and Switzerland that int
Externí odkaz:
http://arxiv.org/abs/astro-ph/9907162