17,305 research outputs found
Detectability of f-mode Unstable Neutron Stars by the Schenberg Spherical Antenna
The Brazilian spherical antenna (Schenberg) is planned to detect high
frequency gravitational waves (GWs) ranging from 3.0 kHz to 3.4 kHz. There is a
host of astrophysical sources capable of being detected by the Brazilian
antenna, namely: core collapse in supernova events; (proto)neutron stars
undergoing hydrodynamical instability; f-mode unstable neutron stars, caused by
quakes and oscillations; excitation of the first quadrupole normal mode of 4-9
solar mass black holes; coalescence of neutron stars and/or black holes; exotic
sources such as bosonic or strange matter stars rotating at 1.6 kHz; and
inspiralling of mini black hole binaries. We here address our study in
particular to the neutron stars, which could well become f-mode unstable
producing therefore GWs. We estimate, for this particular source of GWs, the
event rates that in principle can be detected by Schenberg and by the Dutch
Mini-Grail antenna.Comment: 7 pages, 3 figures; Classical and Quantum Gravity (in press
A formulation of a (q+1,8)-cage
Let be a prime power. In this note we present a formulation for
obtaining the known -cages which has allowed us to construct small
--graphs for and . Furthermore, we also obtain smaller
-graphs for even prime power .Comment: 14 pages, 2 figure
A construction of small (q-1)-regular graphs of girth 8
In this note we construct a new infinite family of -regular graphs of
girth and order for all prime powers , which are the
smallest known so far whenever is not a prime power or a prime power plus
one itself.Comment: 8 pages, 2 figure
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