arXiv subjects

E. M. Popescu

Publications and source records attributed to E. M. Popescu.

3 recordsLinked to original sources

arXiv2017

Advanced Kelvin Probe Operational Methodology for Space Applications

We present a novel methodology for the operation of macroscopic Kelvin Probe instruments. The methodology is based on the use of a harmonic backing potential signal to drive the tip-sample variable capacitance and on a Fourier representation of the tip current, allows for the operation of the instrument under full control and improves its scanning performance by a factor of 60 or more over that of currently available commercial instruments.

astro-ph.IM↗

arXiv2008

Topological Higher Gauge Theory - from BF to BFCG theory

We study generalizations of 3- and 4-dimensional BF-theory in the context of higher gauge theory. First, we construct topological higher gauge theories as discrete state sum models and explain how they are related to the state sums of Yetter, Mackaay, and Porter. Under certain conditions, we can present their corresponding continuum counterparts in terms of classical Lagrangians. We then explain that two of these models are already familiar from the literature: the SigmaPhiEA-model of 3-dimensional gravity coupled to topological matter, and also a 4-dimensional model of BF-theory coupled to topological matter.

hep-th↗

arXiv2005

Scalar and tensorial topological matter coupled to (2+1)-dimensional gravity:A.Classical theory and global charges

We consider the coupling of scalar topological matter to (2+1)-dimensional gravity. The matter fields consist of a 0-form scalar field and a 2-form tensor field. We carry out a canonical analysis of the classical theory, investigating its sectors and solutions. We show that the model admits both BTZ-like black-hole solutions and homogeneous/inhomogeneous FRW cosmological solutions.We also investigate the global charges associated with the model and show that the algebra of charges is the extension of the Kac-Moody algebra for the field-rigid gauge charges, and the Virasoro algebrafor the diffeomorphism charges. Finally, we show that the model can be written as a generalized Chern-Simons theory, opening the perspective for its formulation as a generalized higher gauge theory.

gr-qc↗