The cocoon emission - an electromagnetic counterpart to gravitational waves from neutron star mergers

Short Gamma-Ray Bursts (SGRBs) are believed to arise from compact binary mergers (either neutron star-neutron star or black hole-neutron star). If so their jets must penetrate outflows that are ejected during the merger. As a jet crosses the ejecta it dissipates its energy, producing a hot cocoon which surrounds it. We present here 3D numerical simulations of jet propagation in mergers' outflows and we calculate the resulting emission. This emission consists of two components: the cooling emission, the leakage of the thermal energy of the hot cocoon, and the cocoon macronova that arises from the radioactive decay of the cocoon's material. This emission gives a brief (~ one hour) blue, wide angle signal. While the parameters of the outflow and jet are uncertain, for the configurations we have considered the signal is bright (~ -14 $-$ -15 absolute magnitude) and outshines all other predicted UV-optical signals. The signal is brighter when the jet breakout time is longer and its peak brightness does not depend strongly on the highly uncertain opacity. A rapid search for such a signal is a promising strategy to detect an electromagnetic merger counterpart. A detected candidate could be then followed by deep IR searches for the longer but weaker macronova arising from the rest of the ejecta.Comment: Accepted for publication in MNRA

A Comparative Analysis of Speech Recognition Platforms

Speech recognition (also known as automatic speech recognition) converts spoken words to text. It is a broad term which means it can recognize almost any speech – such as in a call centre system designed to recognize many voices. Speech Recognition in the field of telephony commonplace; and in the field of computer gaming and simulation, is becoming widespread. People with disabilities are another part of the population that benefit from using speech recognition programs. It is becoming increasingly certain, that the interaction between humans and speech recognition engines is on the increase. In certain circumstances, the caller is directed with a series of options. This is called a Directed Dialog interaction. On the other hand, there are situations where the caller is not limited by pre-defined options; but rather given the opportunity to indicate their intent. This scenario is known as an Open Dialog interaction where the caller indicates their intent orally, and the speech platform is expected to correctly interpret the caller’s intent. Such interpretations are prone to variation in recognition and classification. Even if the application software correctly classifies the caller intent, it may not adequately capture the actual utterance. This paper proposes statistical techniques for measuring the performance of three Speech Recognition engines in a directed-dialog scenario

Intertwining Laplace Transformations of Linear Partial Differential Equations

We propose a generalization of Laplace transformations to the case of linear partial differential operators (LPDOs) of arbitrary order in R^n. Practically all previously proposed differential transformations of LPDOs are particular cases of this transformation (intertwining Laplace transformation, ILT). We give a complete algorithm of construction of ILT and describe the classes of operators in R^n suitable for this transformation. Keywords: Integration of linear partial differential equations, Laplace transformation, differential transformationComment: LaTeX, 25 pages v2: minor misprints correcte