72,556 research outputs found
Spatial CSMA: A Distributed Scheduling Algorithm for the SIR Model with Time-varying Channels
Recent work has shown that adaptive CSMA algorithms can achieve throughput
optimality. However, these adaptive CSMA algorithms assume a rather simplistic
model for the wireless medium. Specifically, the interference is typically
modelled by a conflict graph, and the channels are assumed to be static. In
this work, we propose a distributed and adaptive CSMA algorithm under a more
realistic signal-to-interference ratio (SIR) based interference model, with
time-varying channels. We prove that our algorithm is throughput optimal under
this generalized model. Further, we augment our proposed algorithm by using a
parallel update technique. Numerical results show that our algorithm
outperforms the conflict graph based algorithms, in terms of supportable
throughput and the rate of convergence to steady-state.Comment: This work has been presented at National Conference on Communication,
2015, held at IIT Bombay, Mumbai, Indi
Equivariant cobordism of schemes
We study the equivariant cobordism theory of schemes for action of linear
algebraic groups. We compare the equivariant cobordism theory for the action of
a linear algebraic groups with similar groups for the action of tori and deduce
some consequences for the cycle class map of the classifying space of an
algebraic groups.Comment: This revised version supercedes arxiv:1006:317
Gersten Conjecture For Equivariant K-theory And Applications
For a reductive group scheme over a regular semi-local ring, we prove an
equivarinat version of the Gersten conjecture. We draw some interesting
consequences for the representation rings of such reductive group schemes. We
also prove the rigidity for the equivariant K-theory of reductive group schemes
over a henselian local ring. This is then used to compute the equivariant
K-theory of algebraically closed fields
The Phases of QCD in Heavy Ion Collisions and Compact Stars
I review arguments for the existence of a critical point in the QCD phase
diagram as a function of temperature and baryon chemical potential. I describe
how heavy ion collision experiments at the SPS and RHIC can discover the
tell-tale signatures of such a critical point, thus mapping this region of the
QCD phase diagram. I then review the phenomena expected in cold dense quark
matter: color superconductivity and color-flavor locking. I close with a
snapshot of ongoing explorations of the implications of recent developments in
our understanding of cold dense quark matter for the physics of compact stars.Comment: 29 pages. 4 figures. latex with aipproc. References added and
corrected. One version of this review is to appear in the Comments of Nuclear
and Particle Physics section of Comments on Modern Physics. Other versions
were contributed to the proceedings of the Conference on Intersections of
Nuclear and Particle Physics, Quebec, May 2000 and to the proceedings of the
40th Zakopane School of Theoretical Physics, June 200
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