1,543 research outputs found
A Field Theory for the Read Operator
We introduce a new field theory for studying quantum Hall systems. The
quantum field is a modified version of the bosonic operator introduced by Read.
In contrast to Read's original work we do {\em not} work in the lowest Landau
level alone, and this leads to a much simpler formalism. We identify an
appropriate canonical conjugate field, and write a Hamiltonian that governs the
exact dynamics of our bosonic field operators. We describe a Lagrangian
formalism, derive the equations of motion for the fields and present a family
of mean-field solutions. Finally, we show that these mean field solutions are
precisely the Laughlin states. We do not, in this work, address the treatment
of fluctuations.Comment: 15 pages, Revtex 3.
Landau Level Mixing and Solenoidal Terms in Lowest Landau Level Currents
We calculate the lowest Landau level (LLL) current by working in the full
Hilbert space of a two dimensional electron system in a magnetic field and
keeping all the non-vanishing terms in the high field limit. The answer a) is
not represented by a simple LLL operator and b) differs from the current
operator, recently derived by Martinez and Stone in a field theoretic LLL
formalism, by solenoidal terms. Though that is consistent with the inevitable
ambiguities of their Noether construction, we argue that the correct answer
cannot arise naturally in the LLL formalism.Comment: 12 pages + 2 figures, Revtex 3.0, UIUC preprint P-94-04-029, (to
appear in Mod. Phys. Lett. B
Higgs Localization in Split Fermion Models
The flavor puzzle of the Standard Model is explained in split fermion models
by having the fermions localized and separated in an extra dimension. Many of
these models assume a certain profile for the Higgs VEV, usually uniform, or
confined to a brane, without providing a dynamical realization for it. By
studying the effect of the coupling between the Higgs and the localizer fields,
we obtain these scenarios as results, rather than ansaetze. Moreover, we
discuss other profiles and show that they are phenomenologically viable.Comment: 23 pages, 16 figures, based on an MSc thesi
Effects of a mixed vector-scalar kink-like potential for spinless particles in two-dimensional spacetime
The intrinsically relativistic problem of spinless particles subject to a
general mixing of vector and scalar kink-like potentials () is investigated. The problem is mapped into the exactly solvable
Surm-Liouville problem with the Rosen-Morse potential and exact bounded
solutions for particles and antiparticles are found. The behaviour of the
spectrum is discussed in some detail. An apparent paradox concerning the
uncertainty principle is solved by recurring to the concept of effective
Compton wavelength.Comment: 13 pages, 4 figure
Effective action of a five-dimensional domain wall
We calculate the four-dimensional low-energy effective action for the
perturbations of a two-scalar domain wall model in five dimensions. Comparison
of the effective action to the Nambu-Goto action reveals the presence of an
additional coupling between the light scalar field and the massless translation
mode (branon excitation), which can be written in terms of the curvature scalar
of the induced metric. We comment on the impact of this interaction to branon
physics.Comment: 24 page
Entanglement of Solitons in the Frenkel-Kontorova Model
We investigate entanglement of solitons in the continuum-limit of the
nonlinear Frenkel-Kontorova chain. We find that the entanglement of solitons
manifests particle-like behavior as they are characterized by localization of
entanglement. The von-Neumann entropy of solitons mixes critical with
noncritical behaviors. Inside the core of the soliton the logarithmic increase
of the entropy is faster than the universal increase of a critical field,
whereas outside the core the entropy decreases and saturates the constant value
of the corresponding massive noncritical field. In addition, two solitons
manifest long-range entanglement that decreases with the separation of the
solitons more slowly than the universal decrease of the critical field.
Interestingly, in the noncritical regime of the Frenkel-Kontorova model,
entanglement can even increase with the separation of the solitons. We show
that most of the entanglement of the so-called internal modes of the solitons
is saturated by local degrees of freedom inside the core, and therefore we
suggest using the internal modes as carriers of quantum information.Comment: 16 pages, 22 figure
SU(2) gauge theory of gravity with topological invariants
The most general gravity Lagrangian in four dimensions contains three
topological densities, namely Nieh-Yan, Pontryagin and Euler, in addition to
the Hilbert-Palatini term. We set up a Hamiltonian formulation based on this
Lagrangian. The resulting canonical theory depends on three parameters which
are coefficients of these terms and is shown to admit a real SU(2) gauge
theoretic interpretation with a set of seven first-class constraints. Thus, in
addition to the Newton's constant, the theory of gravity contains three
(topological) coupling constants, which might have non-trivial imports in the
quantum theory.Comment: Based on a talk at Loops-11, Madrid, Spain; To appear in Journal of
Physics: Conference Serie
New Branes and Boundary States
We examine D-branes on , and find a three-brane wrapping the entire
, in addition to 1-branes and instantonic 2-branes previously discussed
in the literature. The three-brane is found using a construction of Maldacena,
Moore, and Seiberg. We show that all these branes satisfy Cardy's condition and
extract the open string spectrum on them.Comment: 18 pages, late
Time-dependent gravitating solitons in five dimensional warped space-times
Time-dependent soliton solutions are explicitly derived in a five-dimensional
theory endowed with one (warped) extra-dimension. Some of the obtained
geometries, everywhere well defined and technically regular, smoothly
interpolate between two five-dimensional anti-de Sitter space-times for fixed
value of the conformal time coordinate. Time dependent solutions containing
both topological and non-topological sectors are also obtained. Supplementary
degrees of freedom can be also included and, in this case, the resulting
multi-soliton solutions may describe time-dependent kink-antikink systems.Comment: 19 pages, 10 figure
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