177 research outputs found
Comments on the Chern-Simons photon term in the QED description of graphene
We revisit the Coleman-Hill theorem in the context of reduced planar QED.
Using the global U(1) Ward identity for this non-local but still gauge
invariant theory, we can confirm that the topological piece of the photon
self-energy at zero momentum does not receive further quantum corrections apart
from the potential one-loop contribution, even when considering the Lorentz
non-invariant case due to the Fermi velocity . This is of relevance to
probe possible time parity odd dynamics in a planar sheet of graphene which has
an effective description in terms of -dimensional planar reduced QED.Comment: New section added, published versio
Langevin dynamics of the deconfinement transition for pure gauge theory
We investigate the effects of dissipation in the deconfinement transition for
pure SU(2) and SU(3) gauge theories. Using an effective theory for the order
parameter, we study its Langevin evolution numerically. Noise effects are
included for the case of SU(2). We find that both dissipation and noise have
dramatic effects on the spinodal decomposition of the order parameter and delay
considerably its thermalization. For SU(3) the effects of dissipation are even
larger than for SU(2).Comment: 4 pages, 3 figures. To appear in the proceedings of I Latin American
Workshop on High Energy Phenomenology (LAWHEP 2005), Porto Alegre, Brazil,
1-3 Dec 2005. v2: minor correction
Possible splitting of deconfinement and chiral transitions in strong magnetic fields in QCD
We show that finite-temperature deconfinement and chiral transitions can
split in a strong enough magnetic field. The splitting in critical temperatures
of these transitions in a constant magnetic field of a typical LHC magnitude is
of the order of 10 MeV. A new deconfined phase with broken chiral symmetry
appears.Comment: 4 pages, 6 figures; talk given by E. S. Fraga at 35th International
Conference of High Energy Physics (ICHEP 2010), July 22-28, 2010, Paris,
Franc
Warm inflation in presence of magnetic fields
We present preliminary results on the possible effects that primordial
magnetic fields can have for a warm inflation scenario, based on global
supersymmetry, with a new-inflation-type potential. This work is motivated by
two considerations: first, magnetic fields seem to be present in the universe
on all scales, which rises the possibility that they could also permeate the
early universe; second, the recent emergence of inflationary models where the
inflaton is not assumed to be isolated but instead it is taken as an
interacting field, even during the inflationary expansion. The effects of
magnetic fields are included resorting to Schwinger proper time method.Comment: Published in AIP Conf. Proc. 1548, 288 (2013), IX Mexican School on
Gravitation and Mathematical Physics: Cosmology for the XXIst Centur
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