Constraints on    and  m from distant Type Ia supernovae and cosmic microwave background anisotropies

AbstractTo investigate whether f(R) gravity can relieve current $$H_0$$ H 0 and $$\sigma _8$$ σ 8 tensions, we constrain the Hu-Sawicki f(R) gravity with Planck-2018 cosmic microwave background and redshift space distortions observations. We find that this model fails to relieve both $$H_0$$ H 0 and $$\sigma _8$$ σ 8 tensions, and that its two typical parameters $$\log _{10}f_{R0}$$ log 10 f R 0 and n are insensitive to other cosmological parameters. Combining the cosmic microwave background, baryon acoustic oscillations, Type Ia supernovae, cosmic chronometers with redshift space distortions observations, we give our best constraint $$\log _{10}f_{R0}<-6.75$$ log 10 f R 0 < - 6.75 at the $$2\sigma $$ 2 σ confidence level.

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IMPROVED LIMITS ON PHOTON VELOCITY OSCILLATIONS

Modern Physics Letters A ◽

10.1142/s021773230200926x ◽

2002 ◽

Vol 17 (38) ◽

pp. 2491-2496 ◽

Cited By ~ 5

Author(s):

ALESSANDRO DE ANGELIS ◽

REYNALD PAIN

Keyword(s):

Cosmic Microwave Background ◽

Cosmological Constant ◽

Active Galactic Nuclei ◽

Gamma Rays ◽

Optical Spectrum ◽

Galactic Nuclei ◽

Type Ia Supernovae ◽

Microwave Background ◽

Type Ia ◽

Ia Supernovae

The mixing of the photon with a hypothetical sterile paraphotonic state would have consequences on the cosmological propagation of photons. The absence of distortions in the optical spectrum of distant Type Ia supernovae allows to extend by two orders of magnitude the previous limit on the Lorentz-violating parameter δ associated to the photon–paraphoton transition, extracted from the absence of distortions in the spectrum of the cosmic microwave background. The new limit is consistent with the interpretation of the dimming of distant Type Ia supernovae as a consequence of a nonzero cosmological constant. Observations of gamma-rays from active galactic nuclei allow to further extend the limit on δ.

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Determining the motion of the Solar system relative to the cosmic microwave background using Type Ia supernovae

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2008.13239.x ◽

2008 ◽

Vol 387 (1) ◽

pp. 371-376 ◽

Cited By ~ 11

Author(s):

Christopher Gordon ◽

Kate Land ◽

Anže Slosar

Keyword(s):

Solar System ◽

Cosmic Microwave Background ◽

Type Ia Supernovae ◽

Microwave Background ◽

Type Ia ◽

Ia Supernovae

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COSMOLOGICAL IMPLICATIONS OF CONFORMAL FIELD THEORY

Modern Physics Letters A ◽

10.1142/s0217732311035389 ◽

2011 ◽

Vol 26 (12) ◽

pp. 893-900 ◽

Cited By ~ 7

Author(s):

ROBERT K. NESBET

Keyword(s):

Gravitational Theory ◽

Type Ia Supernovae ◽

Microwave Background ◽

Conformal Field ◽

Peak Structure ◽

Cosmic Evolution ◽

Type Ia ◽

Dynamical Breaking ◽

Ia Supernovae ◽

Conformal Symmetries

Requiring all massless elementary fields to have conformal scaling symmetry removes the conflict between gravitational theory and the quantum theory of elementary particles and fields. Extending this postulate to the scalar field of the Higgs model, dynamical breaking of both gauge and conformal symmetries determines parameters for the interacting fields. In uniform isotropic geometry a modified Friedmann cosmic evolution equation is derived with nonvanishing cosmological constant. Parameters determined by numerical solution are consistent with empirical data for redshifts z ≤ z* = 1090, including luminosity distances for observed type Ia supernovae and peak structure ratios in the cosmic microwave background (CMB). The theory does not require dark matter.

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COSMOLOGY WITH CLUSTERS OF GALAXIES

International Journal of Modern Physics A ◽

10.1142/s0217751x05023992 ◽

2005 ◽

Vol 20 (06) ◽

pp. 1121-1131

Author(s):

M. DONAHUE

Keyword(s):

Initial Density ◽

Cosmological Parameters ◽

Matter Density ◽

Type Ia Supernovae ◽

Clusters Of Galaxies ◽

Microwave Background ◽

Type Ia ◽

Density Perturbations ◽

The Mean ◽

Ia Supernovae

Cluster observations provide unique and useful constraints on cosmological parameters. The contents of clusters and the rate of their formation are very sensitive to the mean matter density (ΩM and the normalization and shape of the spectrum of initial density perturbations near the size scale of ~8h-1 Mpc . Future and on-going cluster studies constrain ΩΛ (acceleration) and the equation of state of the "dark energy," particularly in conjunction with either constraints from the cosmic microwave background or Type Ia supernovae of white dwarfs.

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Constraints on a Vacuum Energy from Both SNIa and CMB Temperature Observations

Advances in Astronomy ◽

10.1155/2012/528243 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6

Author(s):

Riou Nakamura ◽

E. P. Berni Ann Thushari ◽

Mikio Ikeda ◽

Masa-Aki Hashimoto

Keyword(s):

Vacuum Energy ◽

Thermal Evolution ◽

Type Ia Supernovae ◽

Microwave Background ◽

Cosmic Expansion ◽

Type Ia ◽

Standard Cosmological Model ◽

Temperature Observations ◽

Ia Supernovae ◽

Cmb Temperature

We investigate the cosmic thermal evolution with a vacuum energy which decays into photon at the low redshift. We assume that the vacuum energy is a function of the scale factor that increases toward the early universe. We put on the constraints using recent observations of both type Ia supernovae (SNIa) by Union-2 compilation and the cosmic microwave background (CMB) temperature at the range of the redshift0.01<z<3. From SNIa, we find that the effects of a decaying vacuum energy on the cosmic expansion rate should be very small but could be possible forz<1.5. On the other hand, we obtain the severe constraints for parameters from the CMB temperature observations. Although the temperature can be still lower than the case of the standard cosmological model, it should only affect the thermal evolution at the early epoch.

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