ar X iv : a st ro - p h / 06 11 09 3 v 5 28 N ov 2 00 6 Direct Reconstruction of the Dark Energy Scalar - Field Potential

ar X iv : a st ro - p h / 06 11 09 9 v 1 2 N ov 2 00 6 Nuclear Activity in UZC Compact Groups of Galaxies

ar X iv : a st ro - p h / 06 11 30 3 v 1 9 N ov 2 00 6 Flat rotational curves without dark matter

We consider the singular configurations of gravitating gas [1] which could be used as a model for disk galaxies. The simplest steady configuration , which corresponds to rotation of stars around center gives flat rotational curve, provided the density distrubution has a tail, decaying as 1/r. This result based exclusively on Newtonian gravity and does not involve dark matter.

ar X iv : a st ro - p h / 06 11 49 4 v 1 1 5 N ov 2 00 6 MOND rotation curves of very low mass spiral galaxies

We present MOND analysis for several of the lowest mass disc galaxies currently amenable to such analysis–with (baryonic) masses below 4 · 108M⊙. The agreement is good, extending the validity of MOND and its predicted mass velocity relation, to such low masses. Subject headings: dark matter galaxies: kinematics and dynamics

ar X iv : a st ro - p h / 06 09 69 9 v 1 2 6 Se p 20 06 Dynamical vacuum energy , holographic quintom , and the reconstruction of scalar - field dark energy Xin

When taking the holographic principle into account, the vacuum energy will acquire dynamical property that its equation of state is evolving. The current available observational data imply that the holographic vacuum energy behaves as quintom-type dark energy. We adopt the viewpoint of that the scalar field models of dark energy are effective theories of an underlying theory of dark energy. If ...

ar X iv : a st ro - p h / 06 11 54 4 v 1 1 6 N ov 2 00 6 Discovery of a nearby twin of SN 1987 A ’ s nebula around the