Exponential Cardassian Universe

Abstract

The expectation of explaining cosmological observations without requiring new energy sources is forsooth worthy of investigation. In this letter, a new kind of Cardassian models, called exponential Cardassian models, for the late-time universe are investigated in the context of the spatially flat FRW universe scenario. We fit the exponential Cardassian models to current type Ia supernovae data and find they are consistent with the observations. Furthermore, we point out that the equation-of-state parameter for the effective dark fluid component in exponential Cardassian models can naturally cross the cosmological constant divide $w=-1$ that observations favor mildly without introducing exotic material that destroy the weak energy condition.

14 pages, 5 eps figures, using Latex with elsart.cls; references added ; typos corrected and a dicussion on the CMB spectrum effect is added

References in corpus (37)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• The Cosmological Constant and Dark Energy
• Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
• Cosmological parameters from SDSS and WMAP
• A Phantom Menace? Cosmological consequences of a dark energy component with super-negative equation of state
• Cosmological Constant - the Weight of the Vacuum
• The Supernova Legacy Survey: Measurement of Omega_M, Omega_Lambda and w from the First Year Data Set
• Phantom Energy and Cosmic Doomsday
• Cosmological Results from High-z Supernovae
• Cosmological Tracking Solutions
• New Constraints on ${\Omega }_M$, ${\Omega }_{\Lambda }$, and w from an Independent Set of Eleven High-Redshift Supernovae Observed with HST
• Inhomogeneous Equation of State of the Universe: Phantom Era, Future Singularity and Crossing the Phantom Barrier
• Probing the dark energy: methods and strategies
• Cardassian Expansion: a Model in which the Universe is Flat, Matter Dominated, and Accelerating
• 23 High Redshift Supernovae from the IfA Deep Survey: Doubling the SN Sample at z>0.7
• How to determine an effective potential for a variable cosmological term
• Cosmological parameters from supernova observations: A critical comparison of three data sets
• K-Essential Phantom Energy: Doomsday around the corner?
• Dark-Energy Evolution Across the Cosmological-Constant Boundary
• Attractor Solution of Phantom Field
• Phantom-like GCG and the constraints of its parameters via cosmological dynamics
• Phantom Cosmic Dynamics: Tracking Attractor and Cosmic Doomsday
• Phantom with Born-Infield type Lagrangian
• Phantom Field with O(N) Symmetry in Exponential Potential
• Fluid Interpretation of Cardassian Expansion
• Future Type Ia Supernova Data as Tests of Dark Energy from Modified Friedmann Equations
• Born-Infeld-type phantom on the brane world
• Observational tests of x-matter models
• O(N) quintessence
• Dynamics of Quintessence with Thermal Interactions
• Cardassian Expansion: Dark Energy Density from Modified Friedmann Equations
• The CMB spectrum in Cardassian models
• Combined constraints on Cardassian models from supernovae, CMB and large-scale structure observations
• Asymptotic behavior of Cardassian cosmologies with exponential potentials
• On the Quintessence with Abelian and Non-abelian Symmetry

Cited by in corpus (14)

• Viscous generalized Chaplygin gas
• Interacting Ghost Dark Energy Models with Variable $G$ and $\Lambda$
• Torsion cosmological dynamics
• Phenomenological Varying Modified Chaplygin Gas with Variable $G$ and $\Lambda$: Toy Models for Our Universe
• Cardassian Universe Constrained by Latest Observations
• Traversable holographic dark energy wormholes constrained by astronomical observations
• Statefinder diagnostic in a torsion cosmology
• Global monopole surrounded by quintessence-like matter
• Thermodynamic Origin of the Cardassian Universe
• Late time cosmic acceleration from natural infrared cutoff?
• Viscous Cardassian universe
• Action functional of the Cardassian universe
• Observational constraints and differential diagnosis for cosmic evolutionary models
• Natures of Statefinder Parameters and Om Diagnostic for Cardassian Universe in Horava-Lifshitz Gravity