Geodesic congruences in warped spacetimes

In this article, we explore the kinematics of timelike geodesic congruences in warped five dimensional bulk spacetimes, with and without thick or thin branes. Beginning with geodesic flows in the Randall--Sundrum AdS (Anti de Sitter) geometry without and with branes we find analytical expressions for the expansion scalar and comment on the effects of including thin branes on its evolution. Later, we move on to congruences in more general warped bulk geometries with a cosmological thick brane and a time-dependent extra dimensional scale. Using analytical expressions for the velocity field, we interpret the expansion, shear and rotation (ESR) along the flows, as functions of the extra dimensional coordinate. The evolution of a cross-sectional area orthogonal to the congruence, as seen from a local observer's point of view, is also shown graphically. Finally, the Raychaudhuri and geodesic equations in backgrounds with a thick brane are solved numerically in order to figure out the role of initial conditions (prescribed on the ESR) and spacetime curvature on the evolution of the ESR.Comment: 18 pages, 5 figures, 2 Tables, published versio

Can Musical Emotion Be Quantified With Neural Jitter Or Shimmer? A Novel EEG Based Study With Hindustani Classical Music

The term jitter and shimmer has long been used in the domain of speech and acoustic signal analysis as a parameter for speaker identification and other prosodic features. In this study, we look forward to use the same parameters in neural domain to identify and categorize emotional cues in different musical clips. For this, we chose two ragas of Hindustani music which are conventionally known to portray contrast emotions and EEG study was conducted on 5 participants who were made to listen to 3 min clip of these two ragas with sufficient resting period in between. The neural jitter and shimmer components were evaluated for each experimental condition. The results reveal interesting information regarding domain specific arousal of human brain in response to musical stimuli and also regarding trait characteristics of an individual. This novel study can have far reaching conclusions when it comes to modeling of emotional appraisal. The results and implications are discussed in detail.Comment: 6 pages, 12 figures, Presented in 4th International Conference on Signal Processing and Integrated Networks (SPIN) 201

Affect-LM: A Neural Language Model for Customizable Affective Text Generation

Human verbal communication includes affective messages which are conveyed through use of emotionally colored words. There has been a lot of research in this direction but the problem of integrating state-of-the-art neural language models with affective information remains an area ripe for exploration. In this paper, we propose an extension to an LSTM (Long Short-Term Memory) language model for generating conversational text, conditioned on affect categories. Our proposed model, Affect-LM enables us to customize the degree of emotional content in generated sentences through an additional design parameter. Perception studies conducted using Amazon Mechanical Turk show that Affect-LM generates naturally looking emotional sentences without sacrificing grammatical correctness. Affect-LM also learns affect-discriminative word representations, and perplexity experiments show that additional affective information in conversational text can improve language model prediction

Growth and physical property study of single nanowire (diameter ~ 45nm) of half doped Manganite

We report here the growth and characterization of functional oxide nanowire of hole doped manganite of La0.5Sr0.5MnO3 (LSMO). We also report four probe electrical resistance measurement of single nanowire of LSMO (diameter ~ 45nm) using FIB fabricated electrodes. The wires were fabricated by hydrothermal method using autoclave at a temperature of 270 oC. The elemental analysis and physical property like electrical resistivity were studied at individual nanowire level. The quantitative determination of Mn valency and elemental mapping of constituent elements was done by using Electron Energy Loss Spectroscopy (EELS) in the Scanning Transmission Electron Microscopy (STEM) mode. We addressed the important issue of whether as a result of size reduction the nanowires can retain the desired composition, structure and physical properties. The nanowires used were found to have a ferromagnetic transition (TC) at around 325 K which is very close to the bulk value of around 330 K found in single crystal of the same composition confirming that the functional behavior is likely to be retained even after size reduction of the nanowires to a diameter of 45 nm. The electrical resistivity shows insulating behavior within the temperature range measured, which is very much similar to the bulk system.Comment: 11 pages, 7 figures, accepted in Journal of Nanomaterial