The clustering of galaxies is well characterized by fractal properties, with the presence of an eventual cross-over to homogeneity still a matter of considerable debate. In this letter: are discuss the cosmological implications of a fractal distribution of matter, with a possible cross-over to homogeneity at an undetermined scale R-homo Contrary to what is generally assumed, we show that, even when R-homo --> infinity, this possibility can be treated consistently within the framework of the expanding universe solutions of Friedmann. The fractal is a perturbation to an open cosmology in which the leading homogeneous component is the cosmic background radiation (CBR). This cosmology, inspired by the observed galaxy distributions, provides a simple explanation for the recent data which indicate the absence of deceleration in the expansion (q(0) approximate to 0). Correspondingly the "age problem" is also resolved. Further we show: that the model can be extended back from the curvature-dominated arbitrarily deep into the radiation-dominated era. and we discuss qualitatively the modifications to the physics of the anisotropy of the CBR, nucleosynthesis and structure formation.
Fractal cosmology in an open universe / Joyce, M.; Anderson, P. W.; Montuori, M.; Pietronero, Luciano; SYLOS LABINI, F.. - In: EUROPHYSICS LETTERS. - ISSN 0295-5075. - STAMPA. - 50, issue 3:(2000), pp. 416-422. [10.1209/epl/i2000-00285-3]
Fractal cosmology in an open universe
PIETRONERO, Luciano;
2000
Abstract
The clustering of galaxies is well characterized by fractal properties, with the presence of an eventual cross-over to homogeneity still a matter of considerable debate. In this letter: are discuss the cosmological implications of a fractal distribution of matter, with a possible cross-over to homogeneity at an undetermined scale R-homo Contrary to what is generally assumed, we show that, even when R-homo --> infinity, this possibility can be treated consistently within the framework of the expanding universe solutions of Friedmann. The fractal is a perturbation to an open cosmology in which the leading homogeneous component is the cosmic background radiation (CBR). This cosmology, inspired by the observed galaxy distributions, provides a simple explanation for the recent data which indicate the absence of deceleration in the expansion (q(0) approximate to 0). Correspondingly the "age problem" is also resolved. Further we show: that the model can be extended back from the curvature-dominated arbitrarily deep into the radiation-dominated era. and we discuss qualitatively the modifications to the physics of the anisotropy of the CBR, nucleosynthesis and structure formation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.