Results 121 to 130 of about 89,722 (300)

Observational constraints on power-law cosmologies [PDF]

, 1999
Manoj Kaplinghat, Gary Steigman, I. Tkachev, Terry P. Walker   +3 more
openalex   +1 more source

Observing the dark sector

, 2019
Despite the observational success of the standard model of cosmology, present-day observations do not tightly constrain the nature of dark matter and dark energy and modifications to the theory of general relativity.
Marra, Valerio, Rosenfeld, Rogerio, Sturani, Riccardo   +2 more
core   +1 more source

VIS‐to‐MIR reflectance and Raman spectroscopy of the CM2 NWA 12184 carbonaceous chondrite

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 570-595, March 2025.
Abstract The spectral analysis of CM meteorites can help to constrain the mineralogical composition of their parent body, the C‐type asteroids. The CM2 NWA 12184 was spectrally examined employing seven complementary techniques at different spatial resolutions, including VIS‐to‐MIR reflectance and Raman spectroscopy.
A. Galiano, F. Dirri, M. Ferrari, C. Carli, E. Bruschini, G. Filacchione, G. Piccioni, E. Palomba, S. Stefani, A. Raponi, M. Ciarniello, M. E. Palumbo, C. Scirè Scappuzzo, G. Baratta, R. G. Urso, L. Inno   +15 more
wiley   +1 more source

Age of Massive Galaxies at Redshift 8

The Astrophysical Journal
Recent James Webb Space Telescope data analyses have shown that massive red galaxies existed at redshifts z ≳ 6, a discovery that is difficult to understand in the context of standard cosmology (ΛCDM).
M. López-Corredoira, F. Melia, J.-J. Wei, C.-Y. Gao   +3 more
doaj   +1 more source

Observational Constraints on Cosmological Models [PDF]

, 1995
Τ. Padmanabhan
openalex   +1 more source

Observational tests in cosmology [PDF]

International Astronomical Union Colloquium, 1977
Nous testons les trois paramètres sans dimension décrivant les modèles cosmologiques de Friedmann: le paramètre de décélération 90, la densité Ωo, et le paramètre temps τo = Ho to. N’importe quel choix de deux de ces paramètres, compte-tenu de l’échelle donnée par la constante de Hubble, décrit un modèle d’univers dans le cadre de la relativité ...
openaire   +2 more sources

Observational tests of Baryon symmetric cosmology [PDF]

Observational evidence for Baryon symmetric (matter/antimatter) cosmology and future observational tests are reviewed. The most significant consequences of Baryon symmetric cosmology lie in the prediction of an observable cosmic background of gamma ...
Stecker, F. W.
core   +1 more source

Dark Energy: a Brief Review

, 2012
The problem of dark energy is briefly reviewed in both theoretical and observational aspects. In the theoretical aspect, dark energy scenarios are classified into symmetry, anthropic principle, tuning mechanism, modified gravity, quantum cosmology ...
Li, Miao, Li, Xiao-Dong, Wang, Shuang, Wang, Yi   +3 more
core   +2 more sources

Microtextures and structures in metal–sulfide grains in NWA 869 meteorite and their relation to thermal history of L‐chondrite parent body

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 616-631, March 2025.
Abstract Results of microanalysis study of NWA 869 meteorite, an ordinary chondrite, where silicates, Fe‐Ni alloys, and troilite are major constituents, are reported. The presented study of microtextures in metallic and sulfide grains provides information on processes occurring from the asteroid's accretion, through the impacts until cooling.
Paulina Skirak, Gabriela Opiła, Adam Piestrzyński, Gabriela Kozub‐Budzyń, Czesław Kapusta   +4 more
wiley   +1 more source

An Agnostic Approach to Building Empirical Type Ia Supernova Light Curves: Evidence for Intrinsic Chromatic Flux Variation Using Nearby Supernova Factory Data

The Astrophysical Journal
We present a new empirical Type Ia supernova (SN Ia) model with three chromatic flux variation templates: one phase dependent and two phase independent. No underlying dust extinction model or patterns of intrinsic variability are assumed.
Jared Hand, A. G. Kim, G. Aldering, P. Antilogus, C. Aragon, S. Bailey, C. Baltay, S. Bongard, K. Boone, C. Buton, Y. Copin, S. Dixon, D. Fouchez, E. Gangler, R. Gupta, B. Hayden, W. Hillebrandt, Mitchell Karmen, M. Kowalski, D. Küsters, P.-F. Léget, F. Mondon, J. Nordin, R. Pain, E. Pecontal, R. Pereira, S. Perlmutter, K. A. Ponder, D. Rabinowitz, M. Rigault, D. Rubin, K. Runge, C. Saunders, N. Suzuki, C. Tao, S. Taubenberger, R. C. Thomas, M. Vincenzi, (The Nearby Supernova Factory)   +38 more
doaj   +1 more source