694 research outputs found
Inefficiencies in bargaining - departing from Akerlof and Myerson-Satterthwaite
We consider bargaining problems in which parties have access to
outside options. The size of the pie is commonly known and each party
privately knows the realization of her outside option. Parties are assumed
to have a veto right, which allows them to obtain at least their
outside option payoff in any event. Besides, agents can receive no subsidy
ex post. We show that inefficiencies are inevitable for virtually all
distributions of outside options, as long as the size of the surplus generated
by the agreement is uncertain and may be arbitrarily small for
all realizations of either party’s outside option. Our inefficiency result
holds true whatever the degree of correlation between the distributions
of outside options, and even if it is known for sure that an agreement is
beneficial. The same insights apply to the bargaining between a buyer
and a seller privately informed of their valuations and to public good
problems among agents privately informed of their willingness to pay
Statistics of precursors to fingering processes
We present an analysis of the statistical properties of hydrodynamic field
fluctuations which reveal the existence of precursors to fingering processes.
These precursors are found to exhibit power law distributions, and these power
laws are shown to follow from spatial -Gaussian structures which are
solutions to the generalized non-linear diffusion equation.Comment: 7 pages incl. 5 figs; tp appear in Europhysics Letter
Linear and non linear response in the aging regime of the 1D trap model
We investigate the behaviour of the response function in the one dimensional
trap model using scaling arguments that we confirm by numerical simulations. We
study the average position of the random walk at time tw+t given that a small
bias h is applied at time tw. Several scaling regimes are found, depending on
the relative values of t, tw and h. Comparison with the diffusive motion in the
absence of bias allows us to show that the fluctuation dissipation relation is,
in this case, valid even in the aging regime.Comment: 5 pages, 3 figures, 3 references adde
Rejuvenation in the Random Energy Model
We show that the Random Energy Model has interesting rejuvenation properties
in its frozen phase. Different `susceptibilities' to temperature changes, for
the free-energy and for other (`magnetic') observables, can be computed
exactly. These susceptibilities diverge at the transition temperature, as
(1-T/T_c)^-3 for the free-energy.Comment: 9 pages, 1 eps figur
Multiple scaling regimes in simple aging models
We investigate aging in glassy systems based on a simple model, where a point
in configuration space performs thermally activated jumps between the minima of
a random energy landscape. The model allows us to show explicitly a subaging
behavior and multiple scaling regimes for the correlation function. Both the
exponents characterizing the scaling of the different relaxation times with the
waiting time and those characterizing the asymptotic decay of the scaling
functions are obtained analytically by invoking a `partial equilibrium'
concept.Comment: 4 pages, 3 figure
Aging in Models of Non-linear Diffusion
We show that for a family of problems described by non-linear diffusion
equations an exact calculation of the two time correlation function gives
C(t,t')=f(t-t')g(t'), t>t', exhibiting normal and anomalous diffusions, as well
as aging effects, depending on the degree of non-linearity. We discuss also the
form in which FDT is violated in this class of systems. Finally we argue that
in this type of models aging may be consequence of the non conservation of the
"total mass".Comment: 4 pages, 1 figure, to appear in Phys.Rev.
The noise properties of stochastic processes and entropy production
Based on a Fokker-Planck description of external Ornstein-Uhlenbeck noise and
cross-correlated noise processes driving a dynamical system we examine the
interplay of the properties of noise processes and the dissipative
characteristic of the dynamical system in the steady state entropy production
and flux. Our analysis is illustrated with appropriate examples.Comment: RevTex, 1 figure, To appear in Phys. Rev.
Resonance phenomena in discrete systems with bichromatic input signal
We undertake a detailed numerical study of the twin phenomena of stochastic
and vibrational resonance in a discrete model system in the presence of
bichromatic input signal. A two parameter cubic map is used as the model that
combines the features of both bistable and threshold settings. Our analysis
brings out several interesting results, such as, the existence of a cross over
behaviour from vibrational to stochastic resonance and the possibility of using
stochastic resonance as a filter for the selective detection/transmission of
the component frequencies in a composite signal. The study also reveals a
fundamental difference between the bistable and threshold mechanisms with
respect to amplification of a multi signal input.Comment: 17 pages, 16 figures, submitted to European Physical Journa
Nonequilibrium stochastic processes: Time dependence of entropy flux and entropy production
Based on the Fokker-Planck and the entropy balance equations we have studied
the relaxation of a dissipative dynamical system driven by external
Ornstein-Uhlenbeck noise processes in absence and presence of nonequilibrium
constraint in terms of the thermodynamically inspired quantities like entropy
flux and entropy production. The interplay of nonequilibrium constraint,
dissipation and noise reveals some interesting extremal nature in the time
dependence of entropy flux and entropy production.Comment: RevTex, 17 pages, 9 figures. To appear in Phys. Rev.
- …
