f(R)gravity without a cosmological constant
نویسندگان
چکیده
منابع مشابه
Viable singularity-free f(R) gravity without a cosmological constant.
Several authors have argued that self-consistent f(R) gravity models distinct from the cold dark matter model with a cosmological constant (LambdaCDM) are almost ruled out. Confronting such claims, we present a particular two-parameter f(R) model that (a) is cosmologically viable and distinguishable from LambdaCDM, (b) is compatible with the existence of relativistic stars, (c) is free of singu...
متن کاملModified Gravity: Cosmology without dark matter or a cosmological constant
We explore the cosmological consequences of Modified Gravity (MOG), and find that it provides, using a minimal number of parameters, good fits to data, including CMB temperature anisotropy, galaxy mass power spectrum, and supernova luminosity-distance observations. The MOG cosmology is flat and predicts an age of the universe of ∼ 34 billion years.
متن کاملProposal for a Constant Cosmological Constant
It is proposed that the apparent positive acceleration of the cosmological scale factor is due to the vacuum energy of an incomplete chiral phase transition in a hidden SU(2) sector. Constraints from primordial nucleosynthesis imply that the present metastable phase is in a substantially supercooled state. It is argued that massless chiral condensates can substantially enhance the possibility o...
متن کاملModified Gravity: Cosmology without dark matter or Einstein’s cosmological constant
We explore the cosmological consequences of Modified Gravity (MOG), and find that it provides, using a minimal number of parameters, good fits to data, including CMB temperature anisotropy, galaxy power spectrum, and supernova luminosity-distance observations. The MOG cosmology predicts a flat universe with an accelerating expansion and an age of ∼14 billion years.
متن کاملCosmological Constant ?
We prove that a class of one-loop partition functions found by Dienes, giving rise to a vanishing cosmological constant to one-loop, cannot be realized by a consistent lattice string. The construction of non-supersymmetric string with a vanishing cosmological constant therefore remains as elusive as ever. We also discuss a new test that any one-loop partition function for a lattice string must ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review D
سال: 2006
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.74.087501