Saturday, 28 July 2007

Limits on the Dark Energy Parameters from Cosmic Microwave Background experiments

Dmitri Pogosyan1, J. Richard Bond2, Carlo Contaldi2

1Physics Department, University of Alberta, Edmonton, AB, T6G 2J1, Canada 2CITA, University of Toronto, Toronto, ON, M5S 3H8, Canada

Abstract.


Full suite of the present day Cosmic Microwave background (CMB) data, when combined with weak prior information on the Hubble constant and the age of the Universe, or the Large-Scale structure, provides strong indication for a non-zero density of the vacuum-like dark energy in our universe. This result independently supports the conclusions from Supernovae Ia (SN1a) data. When the model parameter space is extended to allow for the range of the equation of state parameter wQ for the dynamical field Q which gives rise to dark energy, the CMB data is found to give a weak upper bound wQ < −0.4 at 95% CL, however combined with SN1a data it strongly favours wQ < −0.8, consistent with -term like behaviour.

http://arxiv.org/pdf/astro-ph/0301310.pdf

Wednesday, 25 July 2007

TASI LECTURES ON DARK MATTER

KEITH A. OLIVE

William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 USA E-mail: olive@umn.edu

Observational evidence and theoretical motivation for dark matter are presented and connections to the CMB and BBN are made. Problems for baryonic and neutrino dark matter are summarized. Emphasis is placed on the prospects for supersymmetric dark matter.


http://arxiv.org/pdf/astro-ph/0301505.pdf

Friday, 20 July 2007

Dark Energy as a Modification of the Friedmann Equation

By:
Gia Dvali1 and Michael S. Turner2,3

1Center for Cosmology and Particle Physics Department of Physics, New York University New York, NY 10003

2Departments of Astronomy & Astrophysics and of Physics Center for Cosmological Physics and Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637-1433

3NASA/Fermilab Astrophysics Center Fermi National Accelerator Laboratory, Batavia, IL 60510-0500



 http://arxiv.org/pdf/astro-ph/0301510.pdf