Aims. We present broad band optical afterglow observations of a long duration GRB 060124 using the 1.04-m Sampurnanand Telescope at ARIES, Nainital and the 2.01-m HCT at IAO, Hanle, including the earliest ground based observations in R band for this GRB. We determine the decay slope of the light curve at different bands and examine the reality of a proposed jet break. Methods. We use data from ...

Classification performance is often not uniform over the data. Some areas in the input space are easier to classify than others. Features that hold information about the ”difficulty” of the data may be nondiscriminative and are therefore disregarded in the classification process. We propose a meta-learning approach where performance may be improved by post-processing. This improvement is done b...

We calculate many different nova light curves for a variety of white dwarf masses and chemical compositions, with the assumption that free-free emission from optically thin ejecta dominates the continuum flux. We show that all these light curves are homologous and a universal law can be derived by introducing a “time scaling factor.” The template light curve for the universal law has a slope of...

Some progenitor models of gamma-ray bursts (GRBs) (e.g., collapsars) may produce anisotropic jets in which the energy per unit solid angle is a power-law function of the angle (∝ θ −k). We calculate light curves and spectra for GRB afterglows when such jets expand either in the interstellar medium or in the wind medium. In particular, we take into account two kinds of wind: one (n ∝ r −3/2) pos...

Some progenitor models of gamma-ray bursts (GRBs) (e.g., collapsars) may produce anisotropic jets in which the energy per unit solid angle is a power-law function of the angle (∝ θ −k). We calculate light curves and spectra for GRB afterglows when such jets expand either in the interstellar medium or in the wind medium. In particular, we take into account two kinds of wind: one (n ∝ r −3/2) pos...

Some researchers suggest that human well-being is U-shaped through our lives. If it exists, such a curve could be classified as a truly fundamental discovery about humans. Yet sceptics point to the difficulty of relying on questions in which people are asked to describe subjective feelings – and the result is then an impasse. This paper suggests a way to try to break that intellectual deadlock....

This paper proposesa new class of unit quaternion curves in SO(3). A general method is developed that transforms a curve in R3 (defined as a weighted sum of basis functions) into its unit quaternion analogue in SO(3). Applying the method to well-known spline curves (such as Bézier, Hermite, and B-spline curves), we are able to construct various unit quaternion curves which share many important ...