5,690 research outputs found
Second order quantum corrections to the classical reflection factor of the sinh-Gordon model
The sinh-Gordon model on a half-line with integrable boundary conditions is
considered in low order perturbation theory developed in affine Toda field
theory. The quantum corrections to the classical reflection factor of the model
are studied up to the second order in the difference of the two boundary
parameters and to one loop order in the bulk coupling. It is noticed that the
general form of the second order quantum corrections are consistent with
Ghoshal's formula.Comment: 24 pages and 1 figure. LaTex2
First order quantum corrections to the classical reflection factor of the sinh-Gordon model
The sinh-Gordon model is restricted to a half-line by boundary conditions
maintaining integrability. A perturbative calculation of the reflection factor
is given to one loop order in the bulk coupling and to first order in the
difference of the two parameters introduced at the boundary, providing a
further verification of Ghoshal's formula. The calculation is consistent with a
conjecture for the general dependence of the reflection factor on the boundary
parameters and the bulk coupling.Comment: 16 pages, 1 figur
Generalised Calogero-Moser models and universal Lax pair operators
Calogero-Moser models can be generalised for all of the finite reflection
groups. These include models based on non-crystallographic root systems, that
is the root systems of the finite reflection groups, H_3, H_4, and the dihedral
group I_2(m), besides the well-known ones based on crystallographic root
systems, namely those associated with Lie algebras. Universal Lax pair
operators for all of the generalised Calogero-Moser models and for any choices
of the potentials are constructed as linear combinations of the reflection
operators. The consistency conditions are reduced to functional equations for
the coefficient functions of the reflection operators in the Lax pair. There
are only four types of such functional equations corresponding to the
two-dimensional sub-root systems, A_2, B_2, G_2, and I_2(m). The root type and
the minimal type Lax pairs, derived in our previous papers, are given as the
simplest representations. The spectral parameter dependence plays an important
role in the Lax pair operators, which bear a strong resemblance to the Dunkl
operators, a powerful tool for solving quantum Calogero-Moser models.Comment: 37 pages, LaTeX2e, no macro, no figur
Boundary breathers in the sinh-Gordon model
We present an investigation of the boundary breather states of the
sinh-Gordon model restricted to a half-line. The classical boundary breathers
are presented for a two parameter family of integrable boundary conditions.
Restricting to the case of boundary conditions which preserve the \phi -->
-\phi symmetry of the bulk theory, the energy spectrum of the boundary states
is computed in two ways: firstly, by using the bootstrap technique and
subsequently, by using a WKB approximation. Requiring that the two descriptions
of the spectrum agree with each other allows a determination of the
relationship between the boundary parameter, the bulk coupling constant, and
the parameter appearing in the reflection factor derived by Ghoshal to describe
the scattering of the sinh-Gordon particle from the boundary.Comment: 16 pages amslate
Boundary Reflection Matrix for Affine Toda Field Theory
We present one loop boundary reflection matrix for Toda field
theory defined on a half line with the Neumann boundary condition. This result
demonstrates a nontrivial cancellation of non-meromorphic terms which are
present when the model has a particle spectrum with more than one mass. Using
this result, we determine uniquely the exact boundary reflection matrix which
turns out to be \lq non-minimal' if we assume the strong-weak coupling \lq
duality'.Comment: 14 pages, Late
The sine-Gordon model with integrable defects revisited
Application of our algebraic approach to Liouville integrable defects is
proposed for the sine-Gordon model. Integrability of the model is ensured by
the underlying classical r-matrix algebra. The first local integrals of motion
are identified together with the corresponding Lax pairs. Continuity conditions
imposed on the time components of the entailed Lax pairs give rise to the
sewing conditions on the defect point consistent with Liouville integrability.Comment: 24 pages Latex. Minor modifications, added comment
Classical Integrable N=1 and Super Sinh-Gordon Models with Jump Defects
The structure of integrable field theories in the presence of jump defects is
discussed in terms of boundary functions under the Lagrangian formalism.
Explicit examples of bosonic and fermionic theories are considered. In
particular, the boundary functions for the N=1 and N=2 super sinh-Gordon models
are constructed and shown to generate the Backlund transformations for its
soliton solutions. As a new and interesting example, a solution with an
incoming boson and an outgoing fermion for the N=1 case is presented. The
resulting integrable models are shown to be invariant under supersymmetric
transformation.Comment: talk presented at the V International Symposium on Quantum Theory and
Symmetries, Valladolid, Spain, July 22-28,200
The Fate of Primary Iron Sulfides in the CM1 Carbonaceous Chondrites: Effects of Advanced Aqueous Alteration on Primary Components
We have carried out a SEM-EPMA-TEM study to determine the textures and
compositions of relict primary iron sulfides and their alteration products in a
suite of moderately to heavily-altered CM1 carbonaceous chondrites. We observed
four textural groups of altered primary iron sulfides: 1)
pentlandite+phyllosilicate (2P) grains, characterized by pentlandite with
submicron lenses of phyllosilicates, 2) pyrrhotite+pentlandite+magnetite (PPM)
grains, characterized by pyrrhotite-pentlandite exsolution textures with
magnetite veining and secondary pentlandite, 3) pentlandite+serpentine (PS)
grains, characterized by relict pentlandite exsolution, serpentine, and
secondary pentlandite, and 4) pyrrhotite+pentlandite+magnetite+serpentine
(PPMS) grains, characterized by features of both the PPM and PS grains.
We have determined that all four groups were initially primary iron sulfides,
which formed from crystallization of immiscible sulfide melts within silicate
chondrules in the solar nebula. The fact that such different alteration
products could result from the same precursor sulfides within even the same
meteorite sample further underscores the complexity of the aqueous alteration
environment for the CM chondrites. The different alteration reactions for each
textural group place constraints on the mechanisms and conditions of alteration
with evidence for acidic environments, oxidizing environments, and changing
fluid compositions (Ni-bearing and Si-Mg-bearing).Comment: 53 pages, 10 figures, 2 tables, appendix containing 3 additional
figures and 5 additional table
Multisymplectic approach to integrable defects in the sine-Gordon model
Ideas from the theory of multisymplectic systems, introduced recently in integrable systems by the author and Kundu to discuss Liouville integrability in classical field theories with a defect, are applied to the sine-Gordon model. The key ingredient is the introduction of a second Poisson bracket in the theory that allows for a Hamiltonian description of the model that is completely equivalent to the standard one, in the absence of a defect. In the presence of a defect described by frozen Bäcklund transformations, our approach based on the new bracket unifies the various tools used so far to attack the problem. It also gets rid of the known issues related to the evaluation of the Poisson brackets of the defect matrix which involve fields at coinciding space point (the location of the defect). The original Lagrangian approach also finds a nice reinterpretation in terms of the canonical transformation representing the defect conditions
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