Zobrazeno 1 - 10
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pro vyhledávání: '"Turner, Michael S."'
Autor:
Turner, Michael S.
The age of the Universe at a given redshift is a fundamental relationship in cosmology. For many years, the uncertainties in it were dauntingly large, close to a factor of 2. In this age of precision cosmology, they are now at the percent level and d
Externí odkaz:
http://arxiv.org/abs/2403.19100
Autor:
Turner, Michael S.
The past 50 years has seen cosmology go from a field known for the errors being in the exponents to precision science. The transformation, powered by ideas, technology, a paradigm shift and culture change, has revolutionized our understanding of the
Externí odkaz:
http://arxiv.org/abs/2201.04741
Big-bang nucleosynthesis (BBN), today a pillar of modern cosmology, began with the trailblazing 1948 paper of Alpher, Bethe and Gamow. In it, they proposed non-equilibrium nuclear processes in the early Universe ($t \sim 1000\,$sec) and an early radi
Externí odkaz:
http://arxiv.org/abs/2111.14254
Autor:
Turner, Michael S.
The $\rm\Lambda$CDM cosmological model is remarkable: with just 6 parameters it describes the evolution of the Universe from a very early time when all structures were quantum fluctuations on subatomic scales to the present, and it is consistent with
Externí odkaz:
http://arxiv.org/abs/2109.01760
Autor:
Turner, Michael S.
I begin by briefly discussing the first two cosmological paradigms, the hot big-bang model and $\Lambda$CDM. In discussing the third paradigm, I focus on the issues it must address, what its aspirations should be, and how it might be initiated. I end
Externí odkaz:
http://arxiv.org/abs/2109.01717
Publikováno v:
Phys. Rev. D 100, 043545 (2019)
We examine the thermal evolution of particle number densities in the early universe when the particles have a finite diffusion length. Assuming that annihilations are impossible when the mean separation of the particles is larger than their diffusion
Externí odkaz:
http://arxiv.org/abs/1905.06240
Sasankan et al, have recently claimed that there are significant deviations in the phase-space distributions of the kinetic energies of nuclei from the Maxwell-Boltzmann form usually assumed in BBN, and further, that these deviations lead to big chan
Externí odkaz:
http://arxiv.org/abs/1811.04932
Autor:
Kolb, Edward W., Turner, Michael S.
Publikováno v:
Phys. Rev. D 99, 063519 (2019)
The hypothetical $SU(3)$ flavor-singlet dibaryon state $S$ with strangeness $-2$ has been discussed as a dark-matter candidate capable of explaining the curious 5-to-1 ratio of the mass density of dark matter to that of baryons. We study the early-un
Externí odkaz:
http://arxiv.org/abs/1809.06003
Autor:
Neben, Abraham R., Turner, Michael S.
Publikováno v:
ApJ, 769, 133 (2013)
For decades, H_0 and q_0 were the quest of cosmology, as they promised to characterize our "world model" without reference to a specific cosmological framework. Using Monte Carlo simulations, we show that q_0 cannot be directly measured using distanc
Externí odkaz:
http://arxiv.org/abs/1209.0480
Autor:
Turner, Michael S., Huterer, Dragan
Publikováno v:
J.Phys.Soc.Jap.76:111015,2007
A web of interlocking observations has established that the expansion of the Universe is speeding up and not slowing, revealing the presence of some form of repulsive gravity. Within the context of general relativity the cause of cosmic acceleration
Externí odkaz:
http://arxiv.org/abs/0706.2186