18,500 research outputs found
Optimal transportation with traffic congestion and Wardrop equilibria
In the classical Monge-Kantorovich problem, the transportation cost only
depends on the amount of mass sent from sources to destinations and not on the
paths followed by this mass. Thus, it does not allow for congestion effects.
Using the notion of traffic intensity, we propose a variant taking into account
congestion. This leads to an optimization problem posed on a set of probability
measures on a suitable paths space. We establish existence of minimizers and
give a characterization. As an application, we obtain existence and variational
characterization of equilibria of Wardrop type in a continuous space setting
Dynamical analysis for a scalar-tensor model with Gauss-Bonnet and non-minimal couplings
We study the autonomous system for a scalar-tensor model of dark energy with
Gauss-Bonnet and non-minimal couplings. The critical points describe important
stable asymptotic scenarios including quintessence, phantom and de Sitter
attractor solutions. Two functional forms for the coupling functions and the
scalar potential were considered: power-law and exponential functions of the
scalar field. For the exponential functions the existence of stable
quintessence, phantom or de Sitter solutions, allows an asymptotic behavior
where the effective Newtonian coupling becomes constant. The phantom solutions
could be realized without appealing to ghost degrees of freedom. Transient
inflationary and radiation dominated phases can also be described.Comment: 31 pages, 3 figures, to appear in EPJ
A computational approach to the D-module of meromorphic functions
Let be a divisor in . We present methods to compare the
-module of the meromorphic functions to some
natural approximations. We show how the analytic case can be treated with
computations in the Weyl algebra.Comment: 11 page
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