10,779 research outputs found
Computing Black Hole entropy in Loop Quantum Gravity from a Conformal Field Theory perspective
Motivated by the analogy proposed by Witten between Chern-Simons and
Conformal Field Theories, we explore an alternative way of computing the
entropy of a black hole starting from the isolated horizon framework in Loop
Quantum Gravity. The consistency of the result opens a window for the interplay
between Conformal Field Theory and the description of black holes in Loop
Quantum Gravity.Comment: 9 page
Efficiency of internal shocks in magnetized relativistic jets
We study the dynamic and radiative efficiency of conversion of
kinetic-to-thermal/magnetic energy by internal shocks in relativistic
magnetized outflows. A parameter study of a large number of collisions of
cylindrical shells is performed. We explore how, while keeping the total flow
luminosity constant, the variable fluid magnetization influences the efficiency
and find that the interaction of shells in a mildly magnetized jet yields
higher dynamic, but lower radiative efficiency than in a non-magnetized flow. A
multi-wavelength radiative signature of different shell magnetization is
computed assuming that relativistic particles are accelerated at internal
shocks.Comment: 4 pages, 2 figures, proceedings of the meeting "HEPRO III: High
Energy Phenomena in Relativistic Outflows" (Barcelona, June 2011), fixed the
bibliography error
On relativistic approaches to the pion self-energy in nuclear matter
We argue that, in contrast to the non-relativistic approach, a relativistic
evaluation of the nucleon--hole and delta-isobar--nucleon hole contributions to
the pion self-energy incorporates the s-wave scattering, which requires a more
accurate evaluation. Therefore relativistic approach containing only these
diagrams does not describe appropriately the pion self-energy in isospin
symmetric nuclear matter. We conclude that, a correct relativistic approach to
the pion self-energy should involve a more sophisticated calculation in order
to satisfy the known experimental results on the near-threshold behaviour of
the pion-nucleon (forward) scattering amplitude.Comment: 7 pages,1 figur
Bifurcations in the Lozi map
We study the presence in the Lozi map of a type of abrupt order-to-order and
order-to-chaos transitions which are mediated by an attractor made of a
continuum of neutrally stable limit cycles, all with the same period.Comment: 17 pages, 12 figure
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