2009/08/10 by Peter C. Stichel, Stichel, Peter C. · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Relativity and Gravitational Theory #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.48550/arxiv.0908.1303
12 pages
arxiv created 2009/08/10 · openalex publication_date 2009/08/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
After defining conformal Galilean-type algebras for arbitrary dynamical exponent z we consider the particular cases of the conformal Galilei algebra (CGA) and the Schrödinger Lie algebra (sch). Galilei massless particles moving with arbitrary, finite velocity are introduced \begindescription \itemi) in d=2 as a realization of the centrally extended CGA in 6 dimensional phase space, \itemii) in arbitrary spatial dimension d as a realization of the unextended \itsch in 4d dimensional phase space. \enddescription A particle system, minimally coupled to gravity, shows, besides Galilei symmetry, also invariance with respect to arbitrary time dependent translations and to dilations with z = (d +2)/3. The most important physical property of such a self-gravitating system is the appearance of a dynamically generated gravitational mass density of either sign. Therefore, this property may serve as a model for the dark sector of the universe. The cosmological solutions of the corresponding hydrodynamical equations show a deceleration phase for the early universe and an acceleration phase for the late universe. This paper is based, in large part, on a recent work with W.J. Zakrzewski: Can cosmic acceleration be caused by exotic massless particles? arXiv:0904.1375 (astro-ph.CO) [1].