Showing papers by "Debnarayan Jana published in 2004"
TL;DR: Application to the neolithic transition in Europe makes it possible to derive more realistic theoretical values for its wavefront speed than those following from the single-delayed framework presented previously.
Abstract: We present a model in which particles (or individuals of a biological population) disperse with a rest time between consecutive motions (or migrations) which may take several possible values from a discrete set. Particles (or individuals) may also react (or reproduce). We derive a new equation for the effective rest time $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{T}$ of the random walk. Application to the neolithic transition in Europe makes it possible to derive more realistic theoretical values for its wavefront speed than those following from the single-delayed framework presented previously [J. Fort and V. M\'endez, Phys. Rev. Lett. 82, 867 (1999)]. The new results are consistent with the archaeological observations of this important historical process.
55 citations
TL;DR: In this article, a simple scaling form of Mott's formula of conductivity in case of amorphous materials in an arbitrary dimension d for a density of states which has a soft gap at the Fermi energy was presented.
Abstract: We present a simple scaling form of Mott's formula of conductivity in case of amorphous materials in an arbitrary dimension d for a density of states which has a soft gap at the Fermi energy. We also indicate the scaling form of the conductivity at a high electric field. Previously known results can be obtained from this generalised form of the conductivity.
18 citations