The paper deals with unconstrained global minimization of rational functions. A necessary condition is given for the function to have a nite innmum. In case the condition is satissed, the problem is shown to be equivalent to a speciic constrained polynomial optimization problem. In this paper, we solve a relaxation of the latter formulation using semi-deenite programming. In general, the relaxa...

This paper reviews the current status of measurements of galaxy clustering at high redshifts (z > ∼ 0.3). The focus is on the inherent limitations in the observation and interpretation of the “evolution of clustering”. It is likely that results from the first attempts to characterize galaxy clustering beyond the “local” universe have been significantly limited by sample variance, as the difficu...

Although widely used in practice, the behavior and accuracy of the popular module identification technique called modularity maximization is not well understood in practical contexts. Here, we present a broad characterization of its performance in such situations. First, we revisit and clarify the resolution limit phenomenon for modularity maximization. Second, we show that the modularity funct...

This paper deals with critical exponents for a doubly degenerate nonlinear parabolic system coupled via local sources and with inner absorptions under null Dirichlet boundary conditions in a smooth bounded domain. The author first establishes the comparison principle and local existence theorem for the above problem. Then under appropriate hypotheses, the author proves that the solution either ...

Abstract In the context of neutrino factories, we review the solution of the degeneracies in the neutrino oscillation parameters. In particular, we have set limits to sin 2θ13 in order to accomplish the unambiguous determination of θ23 and δ. We have performed two different analysis. In the first, at a baseline of 3000 km, we simulate a measurement of the channels νe → νμ, νe → ντ and νμ → νμ, ...

This review covers age-dating methods applied to young stellar populations in starburst galaxies with ages of 10 yr and less. First, recent advances in stellar modeling, both for the interior and the atmospheres, are discussed and spectral lines and colors suitable for age-dating are identified. These age indicators are then applied to single stellar populations, the simplest building blocks of...

As generalizations of the fermion seniority model, four multi-mode Hamiltonians are considered to investigate some of the consequences of the pairing of parafermions of order two. 2-particle and 4-particle states are explicitly constructed for HA ≡ −G A†A with A† ≡ 12 ∑ m>0 c † mc † −m and the distinct HC ≡ −G C†C with C† ≡ 12 ∑ m>0 c † −mc † m, and for the time-reversal invariant H(−) ≡ −G (A†...

We reexamine the usefulness of fitting blended lightcurve models to microlensing photometric data. We find agreement with previous workers (e.g. Woźniak & Paczyński ) that this is a difficult proposition because of the degeneracy of blend fraction with other fit parameters. We show that follow-up observations at specific point along the lightcurve (peak region and wings) of high magnification e...

Skeletons are powerful geometric abstractions that provide useful representations for a number of geometric operations. The straight skeleton has a lower combinatorial complexity compared with the medial axis. Moreover, while the medial axis of a polyhedron is composed of quadric surfaces the straight skeleton just consist of planar faces. Although there exist several methods to compute the str...

Blazars are the most violent steady/recurrent sources of high-energy gamma-ray emission in the known Universe. They are prominent emitters of electromagnetic radiation throughout the entire electromagnetic spectrum. The observable radiation most likely originates in a relativistic jet oriented at a small angle with respect to the line of sight. This review starts out with a general overview of ...