1,809 research outputs found
Statistical Mechanics Analysis of the Continuous Number Partitioning Problem
The number partitioning problem consists of partitioning a sequence of
positive numbers into two disjoint sets, and
, such that the absolute value of the difference of the sums of
over the two sets is minimized. We use statistical mechanics tools to study
analytically the Linear Programming relaxation of this NP-complete integer
programming. In particular, we calculate the probability distribution of the
difference between the cardinalities of and and show that
this difference is not self-averaging.Comment: 9 pages, 1 figur
Connection between the Affine and Conformal Affine Toda Models and their Hirota's Solution
It is shown that the Affine Toda models (AT) constitute a ``gauge fixed''
version of the Conformal Affine Toda model (CAT). This result enables one to
map every solution of the AT models into an infinite number of solutions of the
corresponding CAT models, each one associated to a point of the orbit of the
conformal group. The Hirota's -function are introduced and soliton
solutions for the AT and CAT models associated to and are constructed.Comment: 11 pages, LaTe
Intrinsec Value of Drugs
A nova versão das Boas Práticas de Distribuição de Medicamentos foi aprovada ao nível da Comunidade Europeia e decorre atualmente a sua implementação ao nível dos diversos países...
Toda and Volterra Lattice Equations from Discrete Symmetries of KP Hierarchies
The discrete models of the Toda and Volterra chains are being constructed out
of the continuum two-boson KP hierarchies. The main tool is the discrete
symmetry preserving the Hamiltonian structure of the continuum models. The
two-boson currents of KP hierarchy are being associated with sites of the
corresponding chain by successive actions of discrete symmetry.Comment: 12 pgs, LaTeX, IFT-P.041/9
Some comments on the bi(tri)-Hamiltonian structure of Generalized AKNS and DNLS hierarchies
We give the correct prescriptions for the terms involving the inverse of the
derivative of the delta function, in the Hamiltonian structures of the AKNS and
DNLS systems, in order for the Jacobi identities to hold. We also establish
that the sl(2) AKNS and DNLS systems are tri-Hamiltonians and construct two
compatible Hamiltonian structures for the sl(3) AKNS system. We also give a
derivation of the recursion operator for the sl(n+1) DNLS system.Comment: 10 pages, LaTe
Higher Grading Conformal Affine Toda Teory and (Generalized) Sine-Gordon/Massive Thirring Duality
Some properties of the higher grading integrable generalizations of the
conformal affine Toda systems are studied. The fields associated to the
non-zero grade generators are Dirac spinors. The effective action is written in
terms of the Wess-Zumino-Novikov-Witten (WZNW) action associated to an affine
Lie algebra, and an off-critical theory is obtained as the result of the
spontaneous breakdown of the conformal symmetry. Moreover, the off-critical
theory presents a remarkable equivalence between the Noether and topological
currents of the model. Related to the off-critical model we define a real and
local Lagrangian provided some reality conditions are imposed on the fields of
the model. This real action model is expected to describe the soliton sector of
the original model, and turns out to be the master action from which we uncover
the weak-strong phases described by (generalized) massive Thirring and
sine-Gordon type models, respectively. The case of any (untwisted) affine Lie
algebra furnished with the principal gradation is studied in some detail.
The example of is presented explicitly.Comment: 28 pages, JHEP styl
On Non-Linear W-Infinity Symmetry of Generalized Liouville and Conformal Toda Models
Invariance under non-linear algebra is shown for
the two-boson Liouville type of model and its algebraic generalizations, the
extended conformal Toda models. The realization of the corresponding generators
in terms of two boson currents within KP hierarchy is presented.Comment: 10 pgs, LaTeX, IFT-P.038/9
Hirota's Solitons in the Affine and the Conformal Affine Toda Models
We use Hirota's method formulated as a recursive scheme to construct complete
set of soliton solutions for the affine Toda field theory based on an arbitrary
Lie algebra. Our solutions include a new class of solitons connected with two
different type of degeneracies encountered in the Hirota's perturbation
approach. We also derive an universal mass formula for all Hirota's solutions
to the Affine Toda model valid for all underlying Lie groups. Embedding of the
Affine Toda model in the Conformal Affine Toda model plays a crucial role in
this analysis.Comment: 36 pages, LaTe
A New Deformation of W-Infinity and Applications to the Two-loop WZNW and Conformal Affine Toda Models
We construct a centerless W-infinity type of algebra in terms of a generator
of a centerless Virasoro algebra and an abelian spin-1 current. This algebra
conventionally emerges in the study of pseudo-differential operators on a
circle or alternatively within KP hierarchy with Watanabe's bracket.
Construction used here is based on a special deformation of the algebra
of area preserving diffeomorphisms of a 2-manifold. We show that
this deformation technique applies to the two-loop WZNW and conformal affine
Toda models, establishing henceforth invariance of these models.Comment: 8 page
Evaluation of the impact of initial red wine composition on changes in color and anthocyanin content during bottle storage
Sixteen commercial red wines, selected to cover a different range of color and total polyphenols index (TPI), were stored at 25 °C during 6 months under controlled and different oxygen additions (0, 1.1, 3.1, 10.6 and 30.4 mg L-1) during the bottling process. Changes in color and the anthocyanic composition were evaluated using transmittance spectra and UPLC-MS-UV/Vis respectively. Results reveal a general pattern in the evolution of wines. However, different patterns of evolution related to initial wine composition, especially to TPI, were observed. Wines with higher TPI had a lower evolution, whereas wines with lower TPI showed a higher evolution and greater variability in behavior. In general, oxygen seemed to accelerate all changes observed during aging although the oxygen effect was more limited than the effect of the storage time. These results are relevant for wine experts and help explain the evolution of wine at the bottling stage
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