1,441 research outputs found
Magnetic properties of the Larkin-Ovchinnikov-Fulde-Ferrell superconducting phase
We compute, at the first order in the fine structure constant, the parameters
of the electromagnetic Lagrangian for the inhomogeneous
Larkin-Ovchinnikov-Fulde-Ferrell phase in Quantum Chromodynamics (QCD) and in
condensed matter. In particular we compute for QCD with two flavors the
dielectric and the magnetic permeability tensors, and for condensed matter
superconductors the penetration depth of external magnetic fields.Comment: 12 page
Algebraic treatment of compactification on noncommutative tori
In this paper we study the compactification conditions of the M theory on
D-dimensional noncommutative tori. The main tool used for this analysis is the
algebra A(Z^D) of the projective representations of the abelian group Z^D. We
exhibit the explicit solutions in the space of the multiplication algebra of
A(Z^D), that is the algebra generated by right and left multiplications.Comment: 8 pages, Latex, shortened version as accepted for publication in
Physics Letter
Projective Group Algebras
In this paper we apply a recently proposed algebraic theory of integration to
projective group algebras. These structures have received some attention in
connection with the compactification of the theory on noncommutative tori.
This turns out to be an interesting field of applications, since the space
of the equivalence classes of the vector unitary irreducible
representations of the group under examination becomes, in the projective case,
a prototype of noncommuting spaces. For vector representations the algebraic
integration is equivalent to integrate over . However, its very
definition is related only at the structural properties of the group algebra,
therefore it is well defined also in the projective case, where the space has no classical meaning. This allows a generalization of the usual group
harmonic analysis. A particular attention is given to abelian groups, which are
the relevant ones in the compactification problem, since it is possible, from
the previous results, to establish a simple generalization of the ordinary
calculus to the associated noncommutative spaces.Comment: 24 pages, Late
A Theory of algebraic integration
In this paper we study the problem of quantizing theories defined over a
nonclassical configuration space. If one follows the path-integral approach,
the first problem one is faced with is the one of definition of the integral
over such spaces. We consider this problem and we show how to define an
integration which respects the physical principle of composition of the
probability amplitudes for a very large class of algebras.Comment: 7 pages, LaTeX (or Latex, etc). Contribution to the Path Integral
from peV to TeV Conference, Florence-Italy, August 25-29, 199
Anisotropic Color Superconductivity
We discuss the possibility that in finite density QCD an anisotropic phase is
realized. This case might arise for quarks with different chemical potential
and/or different masses. In this phase crystalline structures may be formed. We
consider this possibility and we describe, in the context of an effective
lagrangian, the corresponding phonons as the Nambu-Goldstone bosons associated
to the breaking of the space symmetries.Comment: LaTex 17 pages, 6 figures. Contributed paper to the International
Workshop SCGT 02 "Strong Coupling Gauge Theories and Effective Field
Theories", 10-13 December 2002, Nagoya, Japa
Duality in the Color Flavor Locked Spectrum
We analyze the spectrum of the massive states for the color flavor locked
phase (CFL) of QCD. We show that the vector mesons have a mass of the order of
the color superconductive gap . We also see that the excitations
associated with the solitonic sector of the CFL low energy theory have a mass
proportional to and hence are expected to play no role for
the physics of the CFL phase for large chemical potential. Another interesting
point is that the product of the soliton mass and the vector meson mass is
independent of the gap. We interpret this behavior as a form of electromagnetic
duality in the sense of Montonen and Olive. Our approach for determining the
properties of the massive states is non-perturbative in nature and can be
applied to any theory with multiple scales.Comment: RevTeX4, 4 page
On the Ground State of QCD inside a Compact Stellar Object
We describe the effects of the strange quark mass and of the color and
electric neutrality on the superconducing phases of QCD.Comment: Invited talk at the 2006 International Workshop SCGT 06 "Origin of
Mass and Strong Coupling Gauge Theories" 21-24 November 2006, Nagoya, Japan.
Latex file 15 pages. 6 figure
Color superconductivity in high density QCD
In this contributed paper the gapless phases of QCD are discussed.Comment: Contributed paper to the Conference "Quark confinement ant the Hadron
Spectrum VI 2004". Latex, 3 page
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