I argue that string creation may have played a role in reheating the universe after inflation. For strings in four dimensions that arise from branes wrapping cycles in the extra dimensions, estimates from effective field theory show that the string tension need only fall a couple of orders of magnitude below the Planck scale in order for string creation to extract a significant fraction of the ...

Recently S.A. Clark published an interesting duality result in linear conic programming dealing with a convex cone that is not closed in which the usual (algebraic) dual problem is replaced by a topological dual with the aim to have zero duality gap under certain usual hypotheses met in mathematical finance. We present some examples to show that an extra condition is needed for having the concl...

Series connected DC motor is a common nonlinear device mostly used in rated values since its nonlinear modeling makes difficult the efficient velocity control. Local and approximate controllers have been previously applied. In this paper a global nonlinear controller is proposed based on port controlled Hamiltonian systems equivalence, i.e. a suitably defined feedback controller results the ove...

The Original Cosmological Constant As we have seen, in 1917 Einstein boldly launched modern cosmology by applying general relativity to the entire universe. He disposed of the Newtonian problem at infinity by invoking a closed geometry.[2] For his model to be consistent with contemporary astronomical data that suggested a static universe, Einstein reluctantly introduced an extra term that oppos...

Given a convex polygon P with n vertices, the two-center problem is to find two congruent closed disks of minimum radius such that they completely cover P . We propose an algorithm for this problem in the streaming setup, where the input stream is the vertices of the polygon in clockwise order. It produces a radius r satisfying r ≤ 2ropt using O(1) space, where ropt is the optimum solution. Nex...

We consider the proton and neutron quasiparticle orbits around the closed-shell (56)Ni and (48)Ca isotopes. It is found that large model spaces (beyond the capability of shell model applications) are necessary for predicting the quenching of spectroscopic factors. The particle-vibration coupling is identified as the principal mechanism. Additional correlations--due to configuration with several...

We consider the proton and neutron quasiparticle orbits around the closed-shell 56Ni and 48Ca isotopes. It is found that large model spaces (beyond the capability of shell-model applications) are necessary for predicting the quenching of spectroscopic factors. The particle-vibration coupling is identified as the principal mechanism. Additional correlations—due to configuration with several part...

A class of term structure models with volatility of lognormal type is analyzed in the general HJM framework. The corresponding market forward rates do not explode, and are positive and mean reverting. Pricing of caps and floors is consistent with the Black formulas used in the market. Swaptions are priced with closed formulas that reduce (with an extra assumption) to exactly the Black swaption ...

The ExoMol project aims at providing comprehensive line lists of molecular transitions which are likely to be important in the atmospheres of extra-solar planets and cool stars, including brown dwarfs. The physics of the molecules involved varies and can be categories according to the number atoms in the species. Thus the molecules can be grouped as diatomics, both closed and open and shell, tr...

Using the general notions of Batalin, Fradkin, Fradkina and Tyutin to convert second class systems into first class ones, we present a gauge invariant formulation of the massive Yang-Mills theory by embedding it in an extended phase space. The infinite set of correction terms necessary for obtaining the involutive constraints and Hamiltonian is explicitly computed and expressed in a closed form...