Physical parameters for stable f(R) models
Gauranga C. Samanta,Nisha Godani +1 more
TLDR
In this paper, the FRW model is used to study the cosmological implications of the universe with respect to redshift, and the age of universe is predicted in f(R) gravity.Abstract:
Nojiri and Odintsov (Phys Rev D 68:123512, 2003) and Hu and Sawicki (Phys Rev D 76:064004, 2007) have studied nonlinear functions in modified gravity that explain the cosmic acceleration without cosmological constant, fulfill the conditions of local gravity and stability and pass the solar system tests. In this paper, FRW model, a best fitted and fruitful mathematical model of the physical universe (Astrophys J 82:248, 1935; Proc Natl Acad Sci 15:168, 1929; Phys Rev D 73:80, 1948; Astrophys J 142:419, 1965), is studied in the context of these nonlinear functions. The cosmological implications such as Hubble parameter, deceleration parameter, jerk parameter, matter density and the effective equation of state parameter of the universe are plotted with respect to redshift. Subsequently, the age of the universe is predicted in f(R) gravity. All are found to represent the features of present phase of the universe.read more
Citations
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Traversable wormholes in $$R+\alpha R^n$$ gravity
Nisha Godani,Gauranga C. Samanta +1 more
TL;DR: In this article, the authors considered the problem of traversable wormholes in f(R) gravity with the shape function and the energy conditions with respect to both constant and variable redshift functions.
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Static traversable wormholes in f(R,T)=R+2αlnT gravity
Nisha Godani,Gauranga C. Samanta +1 more
TL;DR: In this article, a new form of non-linear f(R, T) function was introduced to obtain the exact wormhole solutions in general relativity and the radius of the throat or the spherical region, with satisfied energy conditions, was determined and the presence of exotic matter was minimized.
Journal ArticleDOI
Static Traversable Wormholes in $f(R, T)=R+2\alpha \ln T$ Gravity
Nisha Godani,Gauranga C. Samanta +1 more
TL;DR: In this paper, a new non-linear shape function was proposed to obtain the exact wormhole solutions in gravity by introducing a new form of nonlinear $f(R,T)$ function.
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Tideless traversable wormholes surrounded by cloud of strings in f(R) gravity
TL;DR: This study deals with the construction of dynamical wormhole that asymptotically approaches a Friedmann-Lemaˆıtre-Robertson-Walker universe.
Journal ArticleDOI
Strange quark matter cosmological models attached to string cloud in f(R) theory of gravity
TL;DR: In this article, the authors examined the Kantowski-Sachs space-time in the presence of strange quark matter with the appearance and nonappearance of strings in f(R) gravity.
References
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Measurements of Omega and Lambda from 42 High-Redshift Supernovae
Saul Perlmutter,Saul Perlmutter,Greg Aldering,Gerson Goldhaber,Gerson Goldhaber,R. A. Knop,Peter Nugent,P. G. Castro,P. G. Castro,Susana E. Deustua,Sebastien Fabbro,Sebastien Fabbro,A. Goobar,A. Goobar,Donald E. Groom,I. M. Hook,I. M. Hook,A. G. Kim,A. G. Kim,A. G. Kim,M. Y. Kim,Julia C. Lee,Julia C. Lee,Nelson J. Nunes,Nelson J. Nunes,Reynald Pain,Reynald Pain,C. R. Pennypacker,C. R. Pennypacker,Robert Quimby,Christopher Lidman,Richard S. Ellis,Mike Irwin,Richard G. McMahon,Pilar Ruiz-Lapuente,Nicholas A. Walton,Bradley E. Schaefer,B. J. Boyle,Alexei V. Filippenko,Thomas Matheson,A. S. Fruchter,Nino Panagia,Nino Panagia,Heidi Jo Newberg,Warrick J. Couch +44 more
TL;DR: In this paper, the mass density, Omega_M, and cosmological-constant energy density of the universe were measured using the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology project.
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Measurements of Omega and Lambda from 42 High-Redshift Supernovae
Saul Perlmutter,Greg Aldering,G. Goldhaber,R. A. Knop,Peter Nugent,P. G. Castro,Susana E. Deustua,Sebastien Fabbro,A. Goobar,D. E. Groom,I. M. Hook,A. G. Kim,M. Y. Kim,Julia C. Lee,Nelson J. Nunes,Reynald Pain,C. R. Pennypacker,R. M. Quimby,C. Lidman,Richard S. Ellis,Michael G. Irwin,Richard G. McMahon,P. Ruiz-Lapuente,Nicholas A. Walton,Bradley E. Schaefer,B. J. Boyle,Alexei V. Filippenko,Thomas Matheson,A. S. Fruchter,Nino Panagia,Heidi Jo Newberg,W. J. Couch +31 more
TL;DR: In this paper, the mass density, Omega_M, and cosmological-constant energy density of the universe were measured by the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology Project.
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A new type of isotropic cosmological models without singularity
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Nine-year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
Gary Hinshaw,Davin Larson,Eiichiro Komatsu,David N. Spergel,David N. Spergel,Charles L. Bennett,Joanna Dunkley,Michael R. Nolta,Mark Halpern,Robert S. Hill,N. Odegard,Lyman A. Page,Kendrick M. Smith,Kendrick M. Smith,Janet L. Weiland,B. Gold,N. Jarosik,Alan J. Kogut,Michele Limon,S. S. Meyer,Gregory S. Tucker,Edward J. Wollack,Edward L. Wright +22 more
TL;DR: In this paper, the authors present cosmological parameter constraints based on the final nine-year WMAP data, in conjunction with a number of additional cosmology data sets.
Journal ArticleDOI
First year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Preliminary maps and basic results
Charles L. Bennett,Mark Halpern,Gary Hinshaw,N. Jarosik,Alan J. Kogut,Michele Limon,Michele Limon,S. S. Meyer,Lyman A. Page,David N. Spergel,Gregory S. Tucker,Gregory S. Tucker,Gregory S. Tucker,Edward J. Wollack,Edward L. Wright,Cris W. Barnes,M. R. Greason,Robert S. Hill,Eiichiro Komatsu,M. R. Nolta,N. Odegard,Hiranya V. Peiris,Licia Verde,Janet Weiland +23 more
TL;DR: In this paper, the authors present full sky microwave maps in five frequency bands (23 to 94 GHz) from the WMAP first year sky survey, which are consistent with the 7 in. full-width at half-maximum (FWHM) Cosmic Background Explorer (COBE) maps.