36,458 research outputs found
Mapping multiplicative to additive noise
The Langevin formulation of a number of well-known stochastic processes
involves multiplicative noise. In this work we present a systematic mapping of
a process with multiplicative noise to a related process with additive noise,
which may often be easier to analyse. The mapping is easily understood in the
example of the branching process. In a second example we study the random
neighbour (or infinite range) contact process which is mapped to an
Ornstein-Uhlenbeck process with absorbing wall. The present work might shed
some light on absorbing state phase transitions in general, such as the role of
conditional expectation values and finite size scaling, and elucidate the
meaning of the noise amplitude. While we focus on the physical interpretation
of the mapping, we also provide a mathematical derivation.Comment: 22 pages, 4 figures, IOP styl
Additive noise quenches delay-induced oscillations
Noise has significant impact on nonlinear phenomena. Here we demonstrate
that, in opposition to previous assumptions, additive noise interfere with the
linear stability of scalar nonlinear systems when these are subject to time
delay. We show this by performing a recently designed time-dependent delayed
center manifold (DCM) reduction around an Hopf bifurcation in a model of
nonlinear negative feedback. Using this, we show that noise intensity must be
considered as a bifurcation parameter and thus shifts the threshold at which
emerge delay-induced rhythmic solutions.Comment: pre-print submitted versio
Consistency of Causal Inference under the Additive Noise Model
We analyze a family of methods for statistical causal inference from sample
under the so-called Additive Noise Model. While most work on the subject has
concentrated on establishing the soundness of the Additive Noise Model, the
statistical consistency of the resulting inference methods has received little
attention. We derive general conditions under which the given family of
inference methods consistently infers the causal direction in a nonparametric
setting
Phase Ordering in Chaotic Map Lattices with Additive Noise
We present some result about phase separation in coupled map lattices with
additive noise. We show that additive noise acts as an ordering agent in this
class of systems. In particular, in the weak coupling region, a suitable
quantity of noise leads to complete ordering. Extrapolating our results at
small coupling, we deduce that this phenomenon could take place also in the
limit of zero coupling.Comment: 8 pages, 7 figure
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