arXiv subjects

M. J. Valtonen

Publications and source records attributed to M. J. Valtonen.

23 records · Page 2Linked to original sources

arXiv2007

Local dark energy: HST evidence from the vicinity of the M 81/M 82 galaxy group

The Hubble Space Telescope observations of the nearby galaxy group M 81/M 82 and its vicinity indicate that the expansion outflow around the group is dominated by the antigravity of the dark energy background. The local density of dark energy in the area is estimated to be near the global dark energy density or perhaps exactly equal to it. This conclusion agrees with our previous results for the Local group vicinity and the vicinity of the Cen A/M 83 group.

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arXiv2007

Detection of dark energy near the Local Group with the Hubble Space Telescope

We report the detection of dark energy near the Milky Way made with precision observations of the local Hubble flow of expansion. We estimate the local density of dark energy and find that it is near, if not exactly equal to, the global dark energy density. The result is independent of, compatible with, and complementary to the horizon-scale observations in which dark energy was first discovered. Together with the cosmological concordance data, our result forms direct observational evidence for the Einstein antigravity as a universal phenomenon -- in the same sense as the Newtonian universal gravity.

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arXiv2007

Local dark energy: HST evidence from the expansion flow around Cen A/M83 galaxy group

A structure with a massive group in its center and a cool expansion outflow outside is studied around the Cen A galaxy with the use of the Hubble Space Telescope observations. It is demonstrated that the dynamics of the flow is dominated by the antigravity of the dark energy background. The density of dark energy in the cell is estimated to be near the global cosmological density. This agrees with our previous result from the neighborhood of the Local group. A notion of the ``Hubble cell'' is introduced as a building block of the local structure of the universe.

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arXiv2005

The very local Hubble flow: Simulating transition from chaos to order

The physical nature of the very local (<3 Mpc) Hubble flow is studied on the basis of the recent high precision observations in the Local Volume. A model including both analytical treatment and computer simulations describes the flow dynamical evolution from a chaotic Little Bang initial state to the present-day state of a quasi-regular expansion. The two major observational parameters of the flow, which are the rate of expansion and the velocity dispersion, find a clear qualitative and quantitative explanation in the model.

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arXiv2003

The very local Hubble flow: computer simulations of dynamical history

The phenomenon of the very local ($\le3$ Mpc) Hubble flow is studied on the basis of the data of recent precision observations. A set of computer simulations is performed to trace the trajectories of the flow galaxies back in time to the epoch of the formation of the Local Group. It is found that the `initial conditions' of the flow are drastically different from the linear velocity-distance relation. The simulations enable also to recognize the major trends of the flow evolution and identify the dynamical role of universal antigravity produced by cosmic vacuum.

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