Jul 20 – 24, 2015
Frankfurt Institute for Advanced Studies
Europe/Berlin timezone

A Modified Exponential Potential for Quintessence

Jul 20, 2015, 4:00 PM
20m
Frankfurt Institute for Advanced Studies

Frankfurt Institute for Advanced Studies

Goethe-Universität FrankfurtCampus Riedberg Ruth-Moufang-Straße 1 60438 Frankfurt am Main GERMANY
Talk Juniors Junior plenary session

Speaker

Dr Hui-Yiing Chang (University of South Carolina Sumter)

Description

We examine a quintessence model with a modified exponential potential given by $V(\phi) = V_0(1 + e^{-\lambda \phi})$. We determine the evolution of the equation of state parameter, $w_\phi$, and the density parameter, $\Omega_\phi$, as a function of the scale factor. Our model, unlike quintessence with a standard exponential potential, can produce an acceptable accelerated expansion at late times. The strongest constraints on the model come from CMB observations, rather than supernova data. The former give the limit $\lambda > 13$. This model provides a partial solution to the coincidence problem, but it does not explain why the accelerated expansion is beginning near the present day.

Primary author

Dr Hui-Yiing Chang (University of South Carolina Sumter)

Co-author

Dr Robert Scherrer (Vanderbilt University)

Presentation materials