978 research outputs found
Tissue specific opsonins for phagocytic cells
Imperial Users onl
Correlation Functions and AdS/LCFT Correspondence
Correlation functions of Logarithmic conformal field theory is investigated
using the ADS/CFT correspondence and a novel method based on nilpotent weights
and 'super fields'. Adding an specific form of interaction, we introduce a
perturbative method to calculate the correlation functions.Comment: 11 pages, 4 figure
Avalanche frontiers in dissipative abelian sandpile model as off-critical SLE(2)
Avalanche frontiers in Abelian Sandpile Model (ASM) are random simple curves
whose continuum limit is known to be a Schramm-Loewner Evolution (SLE) with
diffusivity parameter . In this paper we consider the dissipative
ASM and study the statistics of the avalanche and wave frontiers for various
rates of dissipation. We examine the scaling behavior of a number of functions
such as the correlation length, the exponent of distribution function of loop
lengths and gyration radius defined for waves and avalanches. We find that they
do scale with the rate of dissipation. Two significant length scales are
observed. For length scales much smaller than the correlation length, these
curves show properties close to the critical curves and the corresponding
diffusivity parameter is nearly the same as the critical limit. We interpret
this as the ultra violet (UV) limit where corresponding to .
For length scales much larger than the correlation length we find that the
avalanche frontiers tend to Self-Avoiding Walk, the corresponding driving
function is proportional to the Brownian motion with the diffusion parameter
corresponding to a field theory with . This is the infra
red (IR) limit. Correspondingly the central charge decreases from the IR to the
UV point.Comment: 11 Pages, 6 Figure
Higher Order and boundary Scaling Fields in the Abelian Sandpile Model
The Abelian Sandpile Model (ASM) is a paradigm of self-organized criticality
(SOC) which is related to conformal field theory. The conformal fields
corresponding to some height clusters have been suggested before. Here we
derive the first corrections to such fields, in a field theoretical approach,
when the lattice parameter is non-vanishing and consider them in the presence
of a boundary.Comment: 7 pages, no figure
Spanning Trees in Random Satisfiability Problems
Working with tree graphs is always easier than with loopy ones and spanning
trees are the closest tree-like structures to a given graph. We find a
correspondence between the solutions of random K-satisfiability problem and
those of spanning trees in the associated factor graph. We introduce a modified
survey propagation algorithm which returns null edges of the factor graph and
helps us to find satisfiable spanning trees. This allows us to study
organization of satisfiable spanning trees in the space spanned by spanning
trees.Comment: 12 pages, 5 figures, published versio
Simplifying Random Satisfiability Problem by Removing Frustrating Interactions
How can we remove some interactions in a constraint satisfaction problem
(CSP) such that it still remains satisfiable? In this paper we study a modified
survey propagation algorithm that enables us to address this question for a
prototypical CSP, i.e. random K-satisfiability problem. The average number of
removed interactions is controlled by a tuning parameter in the algorithm. If
the original problem is satisfiable then we are able to construct satisfiable
subproblems ranging from the original one to a minimal one with minimum
possible number of interactions. The minimal satisfiable subproblems will
provide directly the solutions of the original problem.Comment: 21 pages, 16 figure
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