Future Type Ia Supernova Data as Tests of Dark Energy from Modified Friedmann Equations

Details Future Type Ia Supernova Data as Tests of Dark Energy from Modified Friedmann Equations Future Type Ia Supernova Data as Tests of Dark Energy from Modified Friedmann Equations

2003-02-04

arxiv.org/abs/astro-ph/0302064v2

Astrophys.J. 594 (2003) 25-32

Astronomy and Astrophysics

Astrophysics

revised version accepted by ApJ

Scientific paper

10.1086/376899

In the Cardassian model, dark energy density arises from modifications to the Friedmann equation, which becomes $H^2 = g(\rhom)$, where $g(\rhom)$ is a new function of the energy density. The universe is flat, matter dominated, and accelerating. The distance redshift relation predictions of generalized Cardassian models can be very different from generic quintessence models, and can be differentiated with data from upcoming pencil beam surveys of Type Ia Supernovae such as SNAP. We have found the interesting result that, once $\Omega_m$ is known to 10% accuracy, SNAP will be able to determine the sign of the time dependence of the dark energy density. Knowledge of this sign (which is related to the weak energy condition) will provide a first discrimination between various cosmological models that fit the current observational data (cosmological constant, quintessence, Cardassian expansion). Further, we have performed Monte Carlo simulations to illustrate how well one can reproduce the form of the dark energy density with SNAP. To be concrete we study a class of two parameter ($n$,$q$) generalized Cardassian models that includes the original Cardassian model (parametrized by $n$ only) as a special case. Examples are given of MP Cardassian models that fit current supernovae and CMB data, and prospects for differentiating between MP Cardassian and other models in future data are discussed. We also note that some Cardassian models can satisfy the weak energy condition $w>-1$ even with a dark energy component that has an effective equation of state $w_X < -1$.

Affiliated with

Also associated with

No associations

Rating

Future Type Ia Supernova Data as Tests of Dark Energy from Modified Friedmann Equations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Future Type Ia Supernova Data as Tests of Dark Energy from Modified Friedmann Equations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Future Type Ia Supernova Data as Tests of Dark Energy from Modified Friedmann Equations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-268676