527 research outputs found
Solitons and giants in matrix models
We present a method for solving BPS equations obtained in the
collective-field approach to matrix models. The method enables us to find BPS
solutions and quantum excitations around these solutions in the one-matrix
model, and in general for the Calogero model. These semiclassical solutions
correspond to giant gravitons described by matrix models obtained in the
framework of AdS/CFT correspondence. The two-field model, associated with two
types of giant gravitons, is investigated. In this duality-based matrix model
we find the finite form of the -soliton solution. The singular limit of this
solution is examined and a realization of open-closed string duality is
proposed.Comment: 17 pages, JHEP cls; v2: final version to appear in JHEP, 2 references
added, physical motivation and interpretation clarifie
Density Correlation Functions in Calogero Sutherland Models
Using arguments from two dimensional Yang-Mills theory and the collective
coordinate formulation of the Calogero-Sutherland model, we conjecture the
dynamical density correlation function for coupling and , where is
an integer. We present overwhelming evidence that the conjecture is indeed
correct.Comment: 12 pages phyzzx, CERN-TH/94.7243 One reference change
Waves and Solitons in the Continuum Limit of the Calogero-Sutherland Model
We examine a collection of particles interacting with inverse-square two-body
potentials in the thermodynamic limit. We find explicit large-amplitude density
waves and soliton solutions for the motion of the system. Waves can be
constructed as coherent states of either solitons or phonons. Therefore, either
solitons or phonons can be considered as the fundamental excitations. The
generic wave is shown to correspond to a two-band state in the quantum
description of the system, while the limiting cases of solitons and phonons
correspond to particle and hole excitations.Comment: Version to appear in Physical Rerview Letters; contains some new
results and explanation
Comment on ``Low-dimensional Bose liquids: beyond the Gross-Pitaevskii approximation''
This is a comment on the work of Kolomeisky et al., Phys. Rev. Lett. 85, 1146
(2000). We point out that they are using the wrong form of the energy
functional for one-dimensional fermions. We point out two possible forms of the
energy functional, both of which can be derived from first principles but using
different methods. One is obtained from the collective field theory method,
while the other is derived from the extended Thomas-Fermi method. These two
forms of the energy functional do not support the soliton solutions which are
obtained by Kolomeisky et al.Comment: Revtex, 2 page
SELF-DUAL ANYONS IN UNIFORM BACKGROUND FIELDS
We study relativistic self-dual Chern-Simons-Higgs systems in the presence of
uniform background fields that explicitly break CTP. A rich, but discrete
vacuum structure is found when the gauge symmetry is spontaneously broken,
while the symmetric phase can have an infinite vacuum degeneracy at tree level.
The latter is due to the proliferation of neutral solitonic states that cost
zero energy. Various novel self-dual solitons, such as these, are found in both
the symmetric and the asymmetric phases. Also by considering a similar system
on a two-sphere and the subsequent large sphere limit, we isolate sensible and
finite expressions for the conserved angular and linear momenta, which satisfy
anomalous commutation relations. We conclude with a few remarks on unresolved
issues.Comment: LaTeX, 20 pages, 4 uuencoded figures included
4d-inner-shell ionization of Xe+ ions and subsequent Auger decay
We have studied Xe+4d inner-shell photoionization in a direct experiment on
Xe+ ions, merging an ion and a photon beam and detecting the ejected electrons
with a cylindrical mirror analyzer. The measured 4d photoelectron spectrum is
compared to the 4d core valence double ionization spectrum of the neutral Xe
atom, obtained with a magnetic bottle spectrometer. This multicoincidence
experiment gives access to the spectroscopy of the individual Xe2+4d−15p−1
states and to their respective Auger decays, which are found to present a
strong selectivity. The experimental results are interpreted with the help of
ab initio calculations.1\. Auflag
Different Approaches to Assess the Welfare of Dairy Cows with Some Results in Serbia
In this paper, different methodologies for assessing the welfare of dairy cows, such as Animal Needs Index, system of welfare indicators, system of behaviour indicators and the Welfare Quality® assessment protocol for cattle were discussed. Also, the results of the usage of these methodologies in Serbia were analyzed. In the last several years in the country, numerous studies have been conducted about welfare of dairy cattle. State of welfare of dairy cows, on farms with tied and free system estimated by mentioned methodologies was generally acceptable. The major problems in the welfare of cows are insufficient amounts of floor litter, lack of cow access to outdoor runs or pasture, occurrence of lameness, dystocia, downer cow syndrome and mortality, the manifestation of aggression between the animals and improper relationship between stockmen and animals. On the basis of the results, it can be stated that in Serbia only recently enough attention has been paid to monitoring and understanding the current welfare state of dairy cows, which are the first important steps to achieve improvements in practical terms
A Unified Algebraic Approach to Few and Many-Body Correlated Systems
The present article is an extended version of the paper {\it Phys. Rev.} {\bf
B 59}, R2490 (1999), where, we have established the equivalence of the
Calogero-Sutherland model to decoupled oscillators. Here, we first employ the
same approach for finding the eigenstates of a large class of Hamiltonians,
dealing with correlated systems. A number of few and many-body interacting
models are studied and the relationship between their respective Hilbert
spaces, with that of oscillators, is found. This connection is then used to
obtain the spectrum generating algebras for these systems and make an algebraic
statement about correlated systems. The procedure to generate new solvable
interacting models is outlined. We then point out the inadequacies of the
present technique and make use of a novel method for solving linear
differential equations to diagonalize the Sutherland model and establish a
precise connection between this correlated system's wave functions, with those
of the free particles on a circle. In the process, we obtain a new expression
for the Jack polynomials. In two dimensions, we analyze the Hamiltonian having
Laughlin wave function as the ground-state and point out the natural emergence
of the underlying linear symmetry in this approach.Comment: 18 pages, Revtex format, To appear in Physical Review
Particle Production in Matrix Cosmology
We consider cosmological particle production in 1+1 dimensional string
theory. The process is described most efficiently in terms of anomalies, but we
also discuss the explicit mode expansions. In matrix cosmology the usual vacuum
ambiguity of quantum fields in time-dependent backgrounds is resolved by the
underlying matrix model. This leads to a finite energy density for the "in"
state which cancels the effect of anomalous particle production.Comment: 24 pages, 1 figure; v2: references added, minor change
- …
