Bifurcation in kinetic equation for interacting Fermi systems

The finite duration of collisions appear as time-nonlocality in the kinetic equation. Analyzing the corresponding quantum kinetic equation for dense interacting Fermi systems a delay differential equation is obtained which combines time derivatives with finite time stepping known from the logistic mapping. The responsible delay time is explicitly calculated and discussed. As a novel feature oscillations in the time evolution of the distribution function itself appear and bifurcations up to chaotic behavior can occur. The temperature and density conditions are presented where such oscillations and bifurcations arise indicating an onset of phase transition

Foreign direct investment and spillovers : gradualism may be better

In contrast to the standard literature, we show that the presence of spillovers may justify temporarily restricting the inflow of foreign direct investment. Our argument is based on two stylized features of spillovers: first, technology transfers --- and subsequent spillovers --- are limited by the economy's absorptive capacity; and second, spillovers take time to materialize. By letting capital in more gradually, initial investment has the time to create spillovers --- and upgrade the economy's absorptive capacity --- before further investment occurs. This allows subsequent capital inflows to benefit from greater technology transfers. As a result, the economy converges to a steady state with a superior technology and a greater capital stock.We acknowledge financial support from the European Union Directorate General XII (project SERD-1999-000102) and of the Comunidad de Madrid (project 06/0186/2002

Reparametrization-Invariant Effective Action in Field-Antifield Formalism

We introduce classical and quantum antifields in the reparametrization-invariant effective action, and derive a deformed classical master equation.Comment: 14 pages, LaTeX. v2: Further observations, Added one appendix. v3: Version submitted to IJMPA. v4: Version published in IJMP

Path Integral Formulation with Deformed Antibracket

We propose how to incorporate the Leites-Shchepochkina-Konstein-Tyutin deformed antibracket into the quantum field-antifield formalism.Comment: 13 pages, LaTeX. v2: Added references. To appear in Phys. Lett.

Odd Scalar Curvature in Field-Antifield Formalism

We consider the possibility of adding a Grassmann-odd function \nu to the odd Laplacian. Requiring the total \Delta operator to be nilpotent leads to a differential condition for \nu, which is integrable. It turns out that the odd function \nu is not an independent geometric object, but is instead completely specified by the antisymplectic structure E and the density \rho. The main impact of introducing the \nu term is that it makes compatibility relations between E and \rho obsolete. We give a geometric interpretation of \nu as (minus 1/8 times) the odd scalar curvature of an arbitrary antisymplectic, torsion-free and \rho-compatible connection. We show that the total \Delta operator is a \rho-dressed version of Khudaverdian's \Delta_E operator, which takes semidensities to semidensities. We also show that the construction generalizes to the situation where \rho is replaced by a non-flat line bundle connection F. This generalization is implemented by breaking the nilpotency of \Delta with an arbitrary Grassmann-even second-order operator source.Comment: 23 pages, LaTeX. v2: More material added. v3: Reference added. v4: Grant number added. v5: Minor changes. v6: Stylistic change