Classical and Quantum Aspects of Gravitation and Cosmology

These are the proceedings of the XVIII Conference of the Indian Association for General Relativity and Gravitation (IAGRG) held at the Institute of Mathematical Sciences, Madras, INDIA during Feb. 15-17, 1996. The Conference was dedicated the late Prof. S. Chandrasekhar. The proceedings consists of 17 articles on: - Chandrasekhar's work (N. Panchapkesan); - Vaidya-Raychaudhuri Lecture (C.V. Vishveshwara) - Gravitational waves (B.R. Iyer, R. Balasubramanian) - Gravitational Collapse (T.P. Singh) - Accretion on black hole (S. Chakrabarti) - Cosmology (D. Munshi, S. Bharadwaj, G.S. Mohanty, P. Bhattacharjee); - Classical GR (S. Kar, D.C. Srivatsava) - Quantum aspects (J. Maharana, Saurya Das, P. Mitra, G. Date, N.D. Hari Dass) The body of THIS article contains ONLY the title, contents, foreword, organizing committees, preface, list of contributed talks and list of participants. The plenery talks are available at: http://www.imsc.ernet.in/physweb/Conf/ both as post-script files of individual articles and also as .uu source files. For further information please send e-mail to [email protected]: 12 pages, latex, needs psfig.tex macros. Latex the file run.tex. These Proceedings of the XVIII IAGRG Conference are available at http://www.imsc.ernet.in/physweb/Conf/ MINOR TYPO's in the ABSTRACT correcte

Analog-digital simulation of transient-induced logic errors and upset susceptibility of an advanced control system

A simulation study is described which predicts the susceptibility of an advanced control system to electrical transients resulting in logic errors, latched errors, error propagation, and digital upset. The system is based on a custom-designed microprocessor and it incorporates fault-tolerant techniques. The system under test and the method to perform the transient injection experiment are described. Results for 2100 transient injections are analyzed and classified according to charge level, type of error, and location of injection

Radiation reaction in the 2.5PN waveform from inspiralling binaries in circular orbits

In this Comment we compute the contributions of the radiation reaction force in the 2.5 post-Newtonian (PN) gravitational wave polarizations for compact binaries in circular orbits. (i) We point out and correct an inconsistency in the derivation of Arun, Blanchet, Iyer, and Qusailah. (ii) We prove that all contributions from radiation reaction in the 2.5PN waveform are actually negligible since they can be absorbed into a modification of the orbital phase at the 5PN order.Comment: 7 pages, no figures, submitted to CQ

Getting diverse students and staff to talk about integration on campus, and what they say when they do: A UK-India collaborative case study.

This paper reports the early stages of a UKIERI-funded project, ‘Widening Participation: Diversity, isolation or integration in Higher Education?’.The project is concerned with greater equity, social justice, community and social cohesion within the current globalised, market oriented context of higher education (HE), and with enabling students to be better prepared for, and thrive in social networks and work-related arenas which are increasingly diverse, multicultural, interdependent and global. The main aim of this 3 year project is to explore the nature of social cohesion, integration and separation, diversity, equality and discrimination experienced by diverse, minority, disadvantaged and under-represented students attending HE in UK and India. Group stereotypes are often subconsciously held, emerging into consciousness only when they appear confirmed or confounded by personal experience or public events. Where there is little knowledge or personal experience then reliance upon group stereotypes is more likely (Kunda & Thagard, 1996). This can impact upon student and staff expectations of, responses to, and interactions with each other. Individual students’ experiences and perceptions lie at the core of this project, but the ultimate purpose is to illuminate our understanding as to how these are mediated, shaped and formed, in relation to and in interaction with the structures and contextual features of the educational environments in which they, as students, are located. It is thus framed by socio-cultural rather than psychological or therapeutic theories and is located within a social-constructivist perspective (Moore, 2000). Social constructivism facilitates the development of improved understandings of educational and social environments that shape rather than determine individual dispositions towards social diversity encountered on campus. It is highly suited to the understanding of perceptions, and exploring resonances with actions, reactions and interactions. The initial stage of this project involved inviting students and staff (academic and support staff) from five HE colleges and universities in England and India to keep a record (written and photographic) of what for them seemed to be important and relevant events relating to what they saw, heard, did and experienced on campus for a period of 1 month, in teaching, learning and social situations; namely interactions in classes and social settings; what seem to be good experiences and what seem to be negative ones; how and if their particular knowledge and experiences were used, valued and incorporated into their HE experience and learning or how they were negated. A sample size of 90 record keepers was sought across the participating institutions. Getting that sample presented significant difficulties to all but one of the participating institutions, and raised questions about • the methods initially adopted, • the general willingness of students and staff to address and share issues relating to diversity, equality, social cohesion and integration on HE campuses with researchers • cultural differences in accessing respondents to take part in the research Additional data collection methods were adopted and by January 2009 the intended sample size almost met. This paper will address the problems encountered in undertaking the first stage of this research and present initial findings from the data that were eventually obtained

Lagrangian perfect fluids and black hole mechanics

The first law of black hole mechanics (in the form derived by Wald), is expressed in terms of integrals over surfaces, at the horizon and spatial infinity, of a stationary, axisymmetric black hole, in a diffeomorphism invariant Lagrangian theory of gravity. The original statement of the first law given by Bardeen, Carter and Hawking for an Einstein-perfect fluid system contained, in addition, volume integrals of the fluid fields, over a spacelike slice stretching between these two surfaces. When applied to the Einstein-perfect fluid system, however, Wald's methods yield restricted results. The reason is that the fluid fields in the Lagrangian of a gravitating perfect fluid are typically nonstationary. We therefore first derive a first law-like relation for an arbitrary Lagrangian metric theory of gravity coupled to arbitrary Lagrangian matter fields, requiring only that the metric field be stationary. This relation includes a volume integral of matter fields over a spacelike slice between the black hole horizon and spatial infinity, and reduces to the first law originally derived by Bardeen, Carter and Hawking when the theory is general relativity coupled to a perfect fluid. We also consider a specific Lagrangian formulation for an isentropic perfect fluid given by Carter, and directly apply Wald's analysis. The resulting first law contains only surface integrals at the black hole horizon and spatial infinity, but this relation is much more restrictive in its allowed fluid configurations and perturbations than that given by Bardeen, Carter and Hawking. In the Appendix, we use the symplectic structure of the Einstein-perfect fluid system to derive a conserved current for perturbations of this system: this current reduces to one derived ab initio for this system by Chandrasekhar and Ferrari.Comment: 26 pages LaTeX-2

Higher signal harmonics, LISA's angular resolution, and dark energy

It is generally believed that the angular resolution of the Laser Interferometer Space Antenna (LISA) for binary supermassive black holes (SMBH) will not be good enough to identify the host galaxy or galaxy cluster. This conclusion, based on using only the dominant harmonic of the binary SMBH signal, changes substantially when higher signal harmonics are included in assessing the parameter estimation problem. We show that in a subset of the source parameter space the angular resolution increases by more than a factor of 10, thereby making it possible for LISA to identify the host galaxy/galaxy cluster. Thus, LISA's observation of certain binary SMBH coalescence events could constrain the dark energy equation of state to within a few percent, comparable to the level expected from other dark energy missions.Comment: 15 pages, no figures. Final version to appear in Phys. Rev.

Probing the non-linear structure of general relativity with black hole binaries

Observations of the inspiral of massive binary black holes (BBH) in the Laser Interferometer Space Antenna (LISA) and stellar mass binary black holes in the European Gravitational-Wave Observatory (EGO) offer an unique opportunity to test the non-linear structure of general relativity. For a binary composed of two non-spinning black holes, the non-linear general relativistic effects depend only on the masses of the constituents. In a recent letter, we explored the possibility of a test to determine all the post-Newtonian coefficients in the gravitational wave-phasing. However, mutual covariances dilute the effectiveness of such a test. In this paper, we propose a more powerful test in which the various post-Newtonian coefficients in the gravitational wave phasing are systematically measured by treating three of them as independent parameters and demanding their mutual consistency. LISA (EGO) will observe BBH inspirals with a signal-to-noise ratio of more than 1000 (100) and thereby test the self-consistency of each of the nine post-Newtonian coefficients that have so-far been computed, by measuring the lower order coefficients to a relative accuracy of $\sim 10^{-5}$ (respectively, $\sim 10^{-4}$) and the higher order coefficients to a relative accuracy in the range $10^{-4}$-0.1 (respectively, $10^{-3}$-1).Comment: 5 pages, 4 figures. Revised version, accepted for publication in Phys. Rev

Quality control of molluscan shellfish products

Since the molluscan shellfish filter large quantities of water during their feeding process, there are chances of accumulation of toxic heavy metals in their body, if the environment is polluted with toxic metals