Using the INSPIRAL program to search for gravitational waves from low-mass binary inspiral

The INSPIRAL program is the LIGO Scientific Collaboration's computational engine for the search for gravitational waves from binary neutron stars and sub-solar mass black holes. We describe how this program, which makes use of the FINDCHIRP algorithm (discussed in a companion paper), is integrated into a sophisticated data analysis pipeline that was used in the search for low-mass binary inspirals in data taken during the second LIGO science run.Comment: 11 pages, 3 figures, submitted to Classical and Quantum Gravity for the special issue of the GWDAW9 Proceeding

Report on the first binary black hole inspiral search in LIGO data

The LIGO Scientific Collaboration is currently engaged in the first search for binary black hole inspiral signals in real data. We are using the data from the second LIGO science run and we focus on inspiral signals coming from binary systems with component masses between 3 and 20 solar masses. We describe the analysis methods used and report on preliminary estimates for the sensitivities of the LIGO instruments during the second science run.Comment: 10 pages, 2 figures. Added references for section 2, corrected figure 1. To appear in CQG, in a special issue on the proceedings of the 9th Annual Gravitational Wave Data Analysis Workshop (GWDAW), Annecy, France, Dec. 200

Lightcone reference for total gravitational energy

We give an explicit expression for gravitational energy, written solely in terms of physical spacetime geometry, which in suitable limits agrees with the total Arnowitt-Deser-Misner and Trautman-Bondi-Sachs energies for asymptotically flat spacetimes and with the Abbot-Deser energy for asymptotically anti-de Sitter spacetimes. Our expression is a boundary value of the standard gravitational Hamiltonian. Moreover, although it stands alone as such, we derive the expression by picking the zero-point of energy via a ``lightcone reference.''Comment: latex, 7 pages, no figures. Uses an amstex symbo

Methods for Reducing False Alarms in Searches for Compact Binary Coalescences in LIGO Data

The LIGO detectors are sensitive to a variety of noise transients of non-astrophysical origin. Instrumental glitches and environmental disturbances increase the false alarm rate in the searches for gravitational waves. Using times already identified when the interferometers produced data of questionable quality, or when the channels that monitor the interferometer indicated non-stationarity, we have developed techniques to safely and effectively veto false triggers from the compact binary coalescences (CBCs) search pipeline

Center of mass integral in canonical general relativity

For a two-surface B tending to an infinite--radius round sphere at spatial infinity, we consider the Brown--York boundary integral H_B belonging to the energy sector of the gravitational Hamiltonian. Assuming that the lapse function behaves as N \sim 1 in the limit, we find agreement between H_B and the total Arnowitt--Deser--Misner energy, an agreement first noted by Braden, Brown, Whiting, and York. However, we argue that the Arnowitt--Deser--Misner mass--aspect differs from a gauge invariant mass--aspect by a pure divergence on the unit sphere. We also examine the boundary integral H_B corresponding to the Hamiltonian generator of an asymptotic boost, in which case the lapse N \sim x^k grows like one of the asymptotically Cartesian coordinate functions. Such an integral defines the kth component of the center of mass for a Cauchy surface \Sigma bounded by B. In the large--radius limit, we find agreement between H_B and an integral introduced by Beig and O'Murchadha. Although both H_B and the Beig--O'Murchadha integral are naively divergent, they are in fact finite modulo the Hamiltonian constraint. Furthermore, we examine the relationship between H_B and a certain two--surface integral linear in the spacetime Riemann curvature tensor. Similar integrals featuring the curvature appear in works by Ashtekar and Hansen, Penrose, Goldberg, and Hayward. Within the canonical 3+1 formalism, we define gravitational energy and center--of--mass as certain moments of Riemann curvature.Comment: 52 pages, revtex4, uses amsmath and amssym

Status of the joint LIGO--TAMA300 inspiral analysis

We present the status of the joint search for gravitational waves from inspiraling neutron star binaries in the LIGO Science Run 2 and TAMA300 Data Taking Run 8 data, which was taken from February 14 to April 14, 2003, by the LIGO and TAMA collaborations. In this paper we discuss what has been learned from an analysis of a subset of the data sample reserved as a ``playground''. We determine the coincidence conditions for parameters such as the coalescence time and chirp mass by injecting simulated Galactic binary neutron star signals into the data stream. We select coincidence conditions so as to maximize our efficiency of detecting simulated signals. We obtain an efficiency for our coincident search of 78 %, and show that we are missing primarily very distant signals for TAMA300. We perform a time slide analysis to estimate the background due to accidental coincidence of noise triggers. We find that the background triggers have a very different character from the triggers of simulated signals.Comment: 10 page, 8 figures, accepted for publication in Classical and Quantum Gravity for the special issue of the GWDAW9 Proceedings ; Corrected typos, minor change

Quasilocal Thermodynamics of Dilaton Gravity coupled to Gauge Fields

We consider an Einstein-Hilbert-Dilaton action for gravity coupled to various types of Abelian and non-Abelian gauge fields in a spatially finite system. These include Yang-Mills fields and Abelian gauge fields with three and four-form field strengths. We obtain various quasilocal quantities associated with these fields, including their energy and angular momentum, and develop methods for calculating conserved charges when a solution possesses sufficient symmetry. For stationary black holes, we find an expression for the entropy from the micro-canonical form of the action. We also find a form of the first law of black hole thermodynamics for black holes with the gauge fields of the type considered here.Comment: 41 pages, latex, uses fonts provided by AMSTe

A coherent triggered search for single spin compact binary coalescences in gravitational wave data

In this paper we present a method for conducting a coherent search for single spin compact binary coalescences in gravitational wave data and compare this search to the existing coincidence method for single spin searches. We propose a method to characterize the regions of the parameter space where the single spin search, both coincident and coherent, will increase detection efficiency over the existing non-precessing search. We also show example results of the coherent search on a stretch of data from LIGO's fourth science run but note that a set of signal based vetoes will be needed before this search can be run to try to make detections.Comment: 14 pages, 4 figure

The Critical Coupling Likelihood Method: A new approach for seamless integration of environmental and operating conditions of gravitational wave detectors into gravitational wave searches

Any search effort for gravitational waves (GW) using interferometric detectors like LIGO needs to be able to identify if and when noise is coupling into the detector's output signal. The Critical Coupling Likelihood (CCL) method has been developed to characterize potential noise coupling and in the future aid GW search efforts. By testing two hypotheses about pairs of channels, CCL is able to identify undesirable coupled instrumental noise from potential GW candidates. Our preliminary results show that CCL can associate up to $\sim 80$ of observed artifacts with $SNR \geq 8$, to local noise sources, while reducing the duty cycle of the instrument by $\lesssim 15$. An approach like CCL will become increasingly important as GW research moves into the Advanced LIGO era, going from the first GW detection to GW astronomy.Comment: submitted CQ

Statistical Mechanics of Charged Black Holes in Induced Einstein-Maxwell Gravity

The statistical origin of the entropy of charged black holes in models of induced Einstein-Maxwell gravity is investigated. The constituents inducing the Einstein-Maxwell action are charged and interact with an external gauge potential. This new feature, however, does not change divergences of the statistical-mechanical entropy of the constituents near the horizon. It is demonstrated that the mechanism of generation of the Bekenstein-Hawking entropy in induced gravity is universal and it is basically the same for charged and neutral black holes. The concrete computations are carried out for induced Einstein-Maxwell gravity with a negative cosmological constant in three space-time dimensions.Comment: 16 pages, latex, no figure