13,577 research outputs found
Error Propagation in the Hypercycle
We study analytically the steady-state regime of a network of n error-prone
self-replicating templates forming an asymmetric hypercycle and its error tail.
We show that the existence of a master template with a higher non-catalyzed
self-replicative productivity, a, than the error tail ensures the stability of
chains in which m<n-1 templates coexist with the master species. The stability
of these chains against the error tail is guaranteed for catalytic coupling
strengths (K) of order of a. We find that the hypercycle becomes more stable
than the chains only for K of order of a2. Furthermore, we show that the
minimal replication accuracy per template needed to maintain the hypercycle,
the so-called error threshold, vanishes like sqrt(n/K) for large K and n<=4
Finding the Higgs Boson through Supersymmetry
The study of displaced vertices containing two b--jets may provide a double
discovery at the Large Hadron Collider (LHC): we show how it may not only
reveal evidence for supersymmetry, but also provide a way to uncover the Higgs
boson necessary in the formulation of the electroweak theory in a large region
of the parameter space. We quantify this explicitly using the simplest minimal
supergravity model with bilinear breaking of R-parity, which accounts for the
observed pattern of neutrino masses and mixings seen in neutrino oscillation
experiments.Comment: 7 pages, 7 figures. Final version to appear at PRD. Discussion and
results were enlarge
Analysis of dependence among size, rate and duration in internet flows
In this paper we examine rigorously the evidence for dependence among data
size, transfer rate and duration in Internet flows. We emphasize two
statistical approaches for studying dependence, including Pearson's correlation
coefficient and the extremal dependence analysis method. We apply these methods
to large data sets of packet traces from three networks. Our major results show
that Pearson's correlation coefficients between size and duration are much
smaller than one might expect. We also find that correlation coefficients
between size and rate are generally small and can be strongly affected by
applying thresholds to size or duration. Based on Transmission Control Protocol
connection startup mechanisms, we argue that thresholds on size should be more
useful than thresholds on duration in the analysis of correlations. Using
extremal dependence analysis, we draw a similar conclusion, finding remarkable
independence for extremal values of size and rate.Comment: Published in at http://dx.doi.org/10.1214/09-AOAS268 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Dynamics of radiating braneworlds
If the observable universe is a braneworld of Randall-Sundrum type, then
particle interactions at high energies will produce 5-dimensional gravitons
that escape into the bulk. As a result, the Weyl energy density on the brane
does not behave like radiation in the early universe, but does so only later,
in the low energy regime. Recently a simple model was proposed to describe this
modification of the Randall-Sundrum cosmology. We investigate the dynamics of
this model, and find the exact solution of the field equations. We use a
dynamical systems approach to analyze global features of the phase space of
solutions.Comment: error in figures corrected, reference adde
Probing Neutrino Oscillations in Supersymmetric Models at the Large Hadron Collider
The lightest supersymmetric particle may decay with branching ratios that
correlate with neutrino oscillation parameters. In this case the CERN Large
Hadron Collider (LHC) has the potential to probe the atmospheric neutrino
mixing angle with sensitivity competitive to its low-energy determination by
underground experiments. Under realistic detection assumptions, we identify the
necessary conditions for the experiments at CERN's LHC to probe the simplest
scenario for neutrino masses induced by minimal supergravity with bilinear R
parity violation.Comment: 11 pages, 6 figures. To appear in Physical Review
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