400 research outputs found
Dual approaches for defects condensation
We review two methods used to approach the condensation of defects
phenomenon. Analyzing in details their structure, we show that in the limit
where the defects proliferate until occupy the whole space these two methods
are dual equivalent prescriptions to obtain an effective theory for the phase
where the defects (like monopoles or vortices) are completely condensed,
starting from the fundamental theory defined in the normal phase where the
defects are diluted.Comment: 7 pages, major modifications. Version accepted for publication in
Physics Letters
Massive photons and Dirac monopoles: electric condensate and magnetic confinement
We use the generalized Julia-Toulouse approach (GJTA) for condensation of
topological currents (charges or defects) to argue that massive photons can
coexist consistently with Dirac monopoles. The Proca theory is obtained here
via GJTA as a low energy effective theory describing an electric condensate and
the mass of the vector boson is responsible for generating a Meissner effect
which confines the magnetic defects in monopole-antimonopole pairs connected by
physical open magnetic vortices described by Dirac brane invariants, instead of
Dirac strings.Comment: 6 pages, version accepted for publication in Physics Letters
Vanishing DC holographic conductivity from a magnetic monopole condensate
We show how to obtain a vanishing DC conductivity in 3-dimensional strongly
coupled QFT's using a massive 2-form field in the bulk that satisfies a special
kind of boundary condition. The real and imaginary parts of the AC conductivity
are evaluated in this holographic setup and we show that the DC conductivity
identically vanishes even for an arbitrarily small (though nonzero) value of
the 2-form mass in the bulk. We identify the bulk action of the massive 2-form
with an effective theory describing a phase in which magnetic monopoles have
condensed in the bulk. Our results indicate that a condensate of magnetic
monopoles in a 4-dimensional bulk leads to a vanishing DC holographic
conductivity in 3-dimensional strongly coupled QFT's.Comment: 24 pages, 2 figures, accepted for publication in JHE
The BF theory as an electric Julia-Toulouse condensate
The Julia-Toulouse mechanism is used to show that the topological Abelian BF
term may be induced by the condensation of electric charges. As an application
we discuss the subtle question of including consistently magnetic defects into
the Maxwell-BF theory in a way to avoid the usual problems of current
conservation, charge quantization, Elitzur's theorem violation and the reality
of the Dirac brane, produced by the non-minimal coupling. We also discuss a new
way of obtaining the Dirac's veto, which is based on the so-called Dirac brane
symmetry.Comment: 5 pages, reorganized and shortened version accepted for publication
in the Brief Reports section of Physical Review
U(1) effective confinement theory from SU(2) restricted gauge theory via the Julia-Toulouse Approach
We derive an U(1) effective theory of color confinement by applying the
so-called Julia-Toulouse Approach for defects condensation to the SU(2)
restricted gauge theory defined by means of the Cho decomposition of the
non-abelian connection. Cho's geometric construction naturally displays the
topological degrees of freedom of the theory and can be used to put the
Yang-Mills action into an abelianized form under certain conditions. On the
other hand, the use of the Julia-Toulouse prescription to deal with the
monopole condensation leads to an effective action describing the phase whose
dynamics is dominated by the magnetic condensate. The effective theory we found
describes the interaction between external electric currents displaying a
short-range Yukawa interaction plus a linear confinement term that governs the
long distance physics.Comment: 7 page
- …