Power-law Schell-model sources

Realizability condition for electromagnetic Schell-model sources.

The set of functions that appear in the correlation matrix of an electromagnetic source must satisfy the constraint of nonnegative definiteness. Here we derive a necessary and sufficient condition for nonnegativeness for the class of electromagnetic Schell-model sources. This result also suggests a possible synthesis procedure for this type of source. As an illustration, two specific examples o...

Synthesis of electromagnetic Schell-model sources.

A procedure for the synthesis of the most general electromagnetic Schell-model light source is proposed. It makes use of the generalized van Cittert-Zernike theorem to produce the electromagnetic source starting from a primary spatially incoherent source, characterized by a suitable position-dependent polarization matrix. By resorting to the spectral decomposition of the polarization matrix, it...

Mitigation of Potential Environmental Risks of Space Nuclear Power Sources (NPS) Missions in International Law

The Dynamic Power Law Model

I propose a new measure of common, time-varying tail risk for large cross sections of stock returns. Stock return tails are described by a power law in which the power law exponent is allowed to transition smoothly through time as a function of recent data. It is motivated by asset pricing theory and is estimable via quasi-maximum likelihood. Estimates indicate substantial time variation in sto...

Gauss-schell sources as models for synchrotron radiation.

Gauss-Schell light sources are considered as models for synchrotron radiation. These sources can be viewed as random superpositions of coherent Gaussian beams. The relationships of the various widths that can be defined for the description of intensity and coherence, as related to the widths of the electron beam and the single-electron radiation (diffraction) pattern, are summarized. The descri...