35,025 research outputs found
Introduction
This issue of Library Trends, on the theme of Research Into Practice, has been designed with two aims in mind. Published in 2013, it marks the fiftieth anniversary of the founding of the Information School (iSchool) at the University of Sheffield in the United Kingdom by presenting a selection of papers that demonstrate the creativity and variety of research undertaken in the field of librarianship and share a unifying concern to make links, as well as establish meaningful connections, between research and practice. The issue is dedicated to Bob Usherwood, now an emeritus professor in the school, whose work and legacy at Sheffield are distinguished by an exemplary commitment to putting research into practice, and it is especially pleasing for us to be able offer this tribute to Bob in the year when he is due to celebrate his seventieth birthday. We also believe that an issue on this theme is timely and important for our profession. There has been a strong drive lately to promote evidence-based practice in library and information work and to develop a research culture in the practitioner community, exemplified in the United Kingdom by the DREaM project, amid continuing concerns about the disconnect between the research and practitioner communities
High Temperature Asymptotics of Orthogonal Mean-Field Spin Glasses
We evaluate the high temperature limit of the free energy of spin glasses on
the hypercube with Hamiltonian , where the
coupling matrix  is drawn from certain symmetric orthogonally invariant
ensembles. Our derivation relates the annealed free energy of these models to a
spherical integral, and expresses the limit of the free energy in terms of the
limiting spectral measure of the coupling matrix . As an application, we
derive the limiting free energy of the Random Orthogonal Model (ROM) at high
temperatures, which confirms non-rigorous calculations of Marinari et al.
(1994). Our methods also apply to other well-known models of disordered
systems, including the SK and Gaussian Hopfield models.Comment: 15 pages, 1 figur
Majorana Fermion Representation For An Antiferromagnetic Spin-1/2 Chain
We study the 1-dimensional Heisenberg antiferromagnet with s=1/2 using a
Majorana representation of the s=1/2 spins. A simple Hartree-Fock approximation
of the resulting model gives a bilinear fermionic description of the model.
This description is rotationally invariant and gives power-law correlations in
the ``ground state'' in a natural fashion. The excitations are a two-parameter
family of particles, which are spin-1 objects. These are contrasted to the
``spinon'' spectrum, and the technical aspects of the representation are
discussed, including the problem of redundant states.Comment: 24 pages in LaTeX, no figures; some clarifications/additions have
  been made following the referee's comments; to appear in Phys. Rev. 
Loop Variables and Gauge Invariant Interactions - I
We describe a method of writing down interacting equations for all the modes
of the bosonic open string. It is a generalization of the loop variable
approach that was used earlier for the free, and lowest order interacting
cases. The generalization involves, as before, the introduction of a parameter
to label the different strings involved in an interaction. The interacting
string has thus becomes a ``band'' of finite width. The interaction equations
expressed in terms of loop variables, has a simple invariance that is exact
even off shell. A consistent definition of space-time fields requires the
fields to be functions of all the infinite number of gauge coordinates (in
addition to space time coordinates). The theory is formulated in one higher
dimension, where the modes appear massless. The dimensional reduction that is
needed to make contact with string theory (which has been discussed earlier for
the free case) is not discussed here.Comment: 40 pages, Latex. Revised version: some typos corrected. Final version
  to appear in Int. J. of Mod. Phys. 
Background Independent Algebraic Structures in Closed String Field Theory
We construct a Batalin-Vilkovisky (BV) algebra on moduli spaces of Riemann
surfaces. This algebra is background independent in that it makes no reference
to a state space of a conformal field theory. Conformal theories define a
homomorphism of this algebra to the BV algebra of string functionals. The
construction begins with a graded-commutative free associative algebra \C
built from the vector space whose elements are orientable subspaces of moduli
spaces of punctured Riemann surfaces. The typical element here is a surface
with several connected components. The operation  of sewing two
punctures with a full twist is shown to be an odd, second order derivation that
squares to zero. It follows that (\C, \Delta) is a Batalin-Vilkovisky
algebra. We introduce the odd operator , where
 is the boundary operator. It is seen that , and that
consistent closed string vertices define a cohomology class of . This
cohomology class is used to construct a Lie algebra on a quotient space of
\C. This Lie algebra gives a manifestly background independent description of
a subalgebra of the closed string gauge algebra.Comment: phyzzx.tex, MIT-CTP-234
Acknowledgement Patterns in Research Articles: a Bibliometric Study based on Journal of Natural Rubber Research 1986-1997
Analyses the acknowledgements included in the research articles and short communications published in Journal of Natural Rubber Research (1986-1997) in respect of types, frequency of occurrence, individuals acknowledged, etc. Results indicate that 74% items contain acknowledgements; an average acknowledgement per item is 2.2; the most common type of acknowledgments relates to technical support. Peer interactive communication accounts for 44% of the total acknowledgements. The result of the study substantiates the earlier findings that a small number of individuals are highly acknowledged and the rest are acknowledged infrequently
Proper Matter Collineations of Plane Symmetric Spacetimes
We investigate matter collineations of plane symmetric spacetimes when the
energy-momentum tensor is degenerate. There exists three interesting cases
where the group of matter collineations is finite-dimensional. The matter
collineations in these cases are either four, six or ten in which four are
isometries and the rest are proper.Comment: 10 pages, LaTex, accepted for publication in Modern Physics Letters 
Construction of some special subsequences within a Farey sequence
Recently it has been found that some special subsequences within a Farey
sequence play a crucial role in determining the ranges of coupling constant for
which quantum soliton states can exist for an integrable derivative nonlinear
Schrodinger model. In this article, we find a novel mapping which connects two
such subsequences belonging to Farey sequences of different orders. By using
this mapping, we construct an algorithm to generate all of these special
subsequences within a Farey sequence. We also derive the continued fraction
expansions for all the elements belonging to a subsequence and observe a close
connection amongst the corresponding expansion coefficients.Comment: latex, 8 page
A String Motivated Approach to the Relativistic Point Particle
Using concepts developed in string theory, Cohen, Moore, Nelson and
Polchinski calculated the propagator for a relativistic point particle.
Following these authors we extend the technique to include the case of closed
world lines. The partition function found corresponds to the Feynmann and
Schwinger proper time formalism. We also explicitly verify that the partition
function is equivalent to the usual path length action partition function. As
an example of a sum over closed world lines, we compute the Euler-Heisenberg
effective Lagrangian in a novel way.Comment: Talk at Balfest, Salerno 200
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