343,767 research outputs found
Distinguished representations, base change, and reducibility for unitary groups
We show the equality of the local Asai L-functions defined via the
Rankin-Selberg method and the Langlands-Shahidi method for a square integrable
representation of GL(n,E). As a consequence we characterise reducibility of
certain induced representations of U(n,n), and the image of the base change map
from U(n) to GL(n,E) in terms of GL(n,F)-distinguishedness.Comment: 13 page
Reply to Comment on Dirac spectral sum rules for QCD in three dimensions
I reply to the comment by Dr S. Nishigaki (hep-th/0007042) to my papers Phys.
Rev. D61 (2000) 056005 and Phys. Rev. D62 (2000) 016005.Comment: 2 pages, LaTeX, no figure
Gravitational instability and star formation in disk galaxies
We present a general star formation law where star formation rate depends
upon efficiency , timescale of star formation, gas component
of surface mass density and a real exponent . A given exponent
determines which however yields the corresponding star formation
rate. Current nominal Schmidt exponent for our model is .
Based on a gravitational instability parameter and another
dimensionless parameter , where =
pressure, = column density of molecular clouds, we suggest a
general equation for star formation rate which depends upon relative competence
of the two parameters for various physical circumstances. We find that
emerges to be a better parameter for star formation scenario than Toomre
Q-parameter. Star formation rate in the solar neighbourhood is found to be in
good agreement with values inferred from previous studies. Under closed box
approximation model, we obtain a relation between metallicity of gas and the
efficiency of star formation. Our model calculations of metallicity in the
solar neighbourhood agree with earlier estimates. We conclude that metallicity
dispersion for stars of same age may result due to a change in efficiency
through which different sample stars were processed. For no significant change
of metallicity with age, we suggest that all sample stars were born with almost
similar efficiency.Comment: 10 pages, 3 figures, submitted to MNRA
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