Present accelerated expansion of the universe from new Weyl-Integrable gravity approach

We investigate if a recently introduced formulation of general relativity on a Weyl-integrable geometry, contains cosmological solutions exhibiting acceleration in the present cosmic expansion. We derive the general conditions to have acceleration in the expansion of the universe and obtain a particular solution for the Weyl scalar field describing a cosmological model for the present time in concordance with the data combination Planck + WP + BAO + SN.Comment: Version to be published in Eur. Phys. J.

Alexander J. DeVoogt: Limits of the mind: Towards a characterisation of Bao mastership.: Book Review.

Manqala games are played in large parts of Africa, Asia, the Caribbean, South-America and some parts of Europe. Bao is the variation which is found on the East African coast, and only in the Swahili speaking areas. Ways of playing Bao though differ along the coast, and de Voogt focused his research on the sophisticated variant of Zanzibar. The author deals with this Zanzibar variation of Bao in analogy to chess. The first aim of his research project was to find out what distinguishes a master of Bao from an ordinary player. Psychological methods, derived from the study of chess playing are his main methodological instruments, which make the book a remarkable study in the psychology of players, and the role of memory and calculation. His second aim is to introduce Bao to the field of computer games, comparable to computer-based chess

Canonical bases in tensor products revisited

We construct canonical bases in tensor products of several lowest and highest weight integrable modules, generalizing Lusztig's work.Comment: 7 pages, v2, improved exposition, one reference added, to appear in Amer. J. Mat

The California gold rush romance collection (Book Review)

A review of Barratt, A., Bell, A., Christner, D., Harris, L. F., Hickey, C., Hillman, P., ... Wright, J. J. (2016). The California gold rush romance collection. Uhrichsville, OH: Barbour Books. 444 pp. $14.99. ISBN 978163409912

Is cosmic acceleration slowing down?

We investigate the course of cosmic expansion in its `recent past' using the Constitution SN Ia sample (which includes CfA data at low redshifts), jointly with signatures of baryon acoustic oscillations (BAO) in the galaxy distribution and fluctuations in the cosmic microwave background (CMB). Earlier SN Ia data sets could not address this issue because of a paucity of data at low redshifts. Allowing the equation of state of dark energy (DE) to vary, we find that a coasting model of the universe (q_0=0) fits the data about as well as LCDM. This effect, which is most clearly seen using the recently introduced `Om' diagnostic, corresponds to an increase of Om(z) and q(z) at redshifts z \lleq 0.3. In geometrical terms, this suggests that cosmic acceleration may have already peaked and that we are currently witnessing its slowing down. The case for evolving DE strengthens if a subsample of the Constitution set consisting of SNLS+ESSENCE+CfA SN Ia data is analysed in combination with BAO+CMB using the same statistical methods. The effect we observe could correspond to DE decaying into dark matter (or something else). A toy model which mimics this process agrees well with the combined SN Ia+BAO+CMB data.Comment: 6 pages, 5 figures, presentation expanded, results for a new subsample of the Constitution set are added, new BAO data are accounted for, main results unchange