6,095 research outputs found
Mapping of uncertainty relations between continuous and discrete time
Lower bounds on fluctuations of thermodynamic currents depend on the nature
of time: discrete or continuous. To understand the physical reason, we compare
current fluctuations in discrete-time Markov chains and continuous-time master
equations. We prove that current fluctuations in the master equations are
always more likely, due to random timings of transitions. This comparison leads
to a mapping of the moments of a current between discrete and continuous time.
We exploit this mapping to obtain new uncertainty bounds. Our results reduce
the quests for uncertainty bounds in discrete and continuous time to a single
problem.Comment: 5 pages, 3 figure
Asymptotic Bethe Ansatz on the GKP vacuum as a defect spin chain: scattering, particles and minimal area Wilson loops
Moving from Beisert-Staudacher equations, the complete set of Asymptotic
Bethe Ansatz equations and -matrix for the excitations over the GKP vacuum
is found. The resulting model on this new vacuum is an integrable spin chain of
length ( spin) with particle rapidities as inhomogeneities, two
(purely transmitting) defects and (residual R-)symmetry. The
non-trivial dynamics of SYM appears in elaborated dressing factors
of the 2D two-particle scattering factors, all depending on the 'fundamental'
one between two scalar excitations. From scattering factors we determine bound
states. In particular, we study the strong coupling limit, in the
non-perturbative, perturbative and giant hole regimes. Eventually, from these
scattering data we construct the pentagon transition amplitudes
(perturbative regime). In this manner, we detail the multi-particle
contributions (flux tube) to the MHV gluon scattering amplitudes/Wilson loops
(OPE or BSV series) and re-sum them to the Thermodynamic Bubble Ansatz.Comment: 103 pages; typos corrected, references added: journal versio
Error-speed correlations in biopolymer synthesis
Synthesis of biopolymers such as DNA, RNA, and proteins are biophysical
processes aided by enzymes. Performance of these enzymes is usually
characterized in terms of their average error rate and speed. However, because
of thermal fluctuations in these single-molecule processes, both error and
speed are inherently stochastic quantities. In this paper, we study
fluctuations of error and speed in biopolymer synthesis and show that they are
in general correlated. This means that, under equal conditions, polymers that
are synthesized faster due to a fluctuation tend to have either better or worse
errors than the average. The error-correction mechanism implemented by the
enzyme determines which of the two cases holds. For example, discrimination in
the forward reaction rates tends to grant smaller errors to polymers with
faster synthesis. The opposite occurs for discrimination in monomer rejection
rates. Our results provide an experimentally feasible way to identify
error-correction mechanisms by measuring the error-speed correlations.Comment: PDF file consist of the main text (pages 1 to 5) and the
supplementary material (pages 6 to 12). Overall, 7 figures split between main
text and S
On the scattering over the GKP vacuum
By converting the Asymptotic Bethe Ansatz (ABA) of SYM into
non-linear integral equations, we find 2D scattering amplitudes of excitations
on top of the GKP vacuum. We prove that this is a suitable and powerful set-up
for the understanding and computation of the whole S-matrix. We show that all
the amplitudes depend on the fundamental scalar-scalar one.Comment: final version, 14 pages, to appear in Physics Letters
Efficiency of attack strategies on complex model and real-world networks
We investigated the efficiency of attack strategies to network nodes when
targeting several complex model and real-world networks. We tested 5 attack
strategies, 3 of which were introduced in this work for the first time, to
attack 3 model (Erdos and Renyi, Barabasi and Albert preferential attachment
network, and scale-free network configuration models) and 3 real networks
(Gnutella peer-to-peer network, email network of the University of Rovira i
Virgili, and immunoglobulin interaction network). Nodes were removed
sequentially according to the importance criterion defined by the attack
strategy. We used the size of the largest connected component (LCC) as a
measure of network damage. We found that the efficiency of attack strategies
(fraction of nodes to be deleted for a given reduction of LCC size) depends on
the topology of the network, although attacks based on the number of
connections of a node and betweenness centrality were often the most efficient
strategies. Sequential deletion of nodes in decreasing order of betweenness
centrality was the most efficient attack strategy when targeting real-world
networks. In particular for networks with power-law degree distribution, we
observed that most efficient strategy change during the sequential removal of
nodes.Comment: 18 pages, 4 figure
Exact results for the low energy AdS(4)XCP(3) string theory
We derive the Thermodynamic Bethe Ansatz equations for the relativistic sigma
model describing the AdS(4)XCP(3) string II A theory at strong coupling (i.e.
in the Alday-Maldacena decoupling limit). The corresponding Y-system involves
an infinite number of Y functions and is of a new type, although it shares a
peculiar feature with the Y-system for AdS(4)XCP(3). A truncation of the
equations at level p and a further generalisation to generic rank N allow us an
alternative description of the theory as the N=4, p= \infty representative in
an infinite family of models corresponding to the conformal cosets CP(N-1)_p X
U(1), perturbed by a relevant composite field \phi(N,p) =\phi_[CP(N-1)_p] X
\phi[U(1)] that couples the two independent conformal field theories. The
calculation of the ultraviolet central charge confirms the conjecture by Basso
and Rej and the conformal dimension of the perturbing operator, at every N and
p, is obtained using the Y-system periodicity. The conformal dimension of
\phi[CP(N-1)_p] matches that of the field identified by Fendley while
discussing integrability issues for the purely bosonic CP(N-1) sigma model.Comment: Latex fil
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