Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1406.4556

Improved Upper Limits on the Stochastic Gravitational-Wave Background from 2009-2010 LIGO and Virgo Data

The LIGO Scientific Collaboration·the Virgo Collaboration·J. Aasi·B. P. Abbott·R. Abbott·T. Abbott·M. R. Abernathy·T. Accadia·F. Acernese·K. Ackley·C. Adams·T. Adams·P. Addesso·R. X. Adhikari·C. Affeldt·M. Agathos·N. Aggarwal·O. D. Aguiar·A. Ain·P. Ajith·A. Alemic·B. Allen·A. Allocca·D. Amariutei·M. Andersen·R. Anderson·S. B. Anderson·W. G. Anderson·K. Arai·M. C. Araya·C. Arceneaux·J. Areeda·S. M. Aston·P. Astone·P. Aufmuth·C. Aulbert·L. Austin·B. E. Aylott·S. Babak·P. T. Baker·G. Ballardin·S. W. Ballmer·J. C. Barayoga·M. Barbet·B. C. Barish·D. Barker·F. Barone·B. Barr·L. Barsotti·M. Barsuglia·M. A. Barton·I. Bartos·R. Bassiri·A. Basti·J. C. Batch·J. Bauchrowitz·Th. S. Bauer·B. Behnke·M. Bejger·M. G. Beker·C. Belczynski·A. S. Bell·C. Bell·G. Bergmann·D. Bersanetti·A. Bertolini·J. Betzwieser·P. T. Beyersdorf·I. A. Bilenko·G. Billingsley·J. Birch·S. Biscans·M. Bitossi·M. A. Bizouard·E. Black·J. K. Blackburn·L. Blackburn·D. Blair·S. Bloemen·M. Blom·O. Bock·T. P. Bodiya·M. Boer·G. Bogaert·C. Bogan·C. Bond·F. Bondu·L. Bonelli·R. Bonnand·R. Bork·M. Born·V. Boschi·Sukanta Bose·L. Bosi·C. Bradaschia·P. R. Brady·V. B. Braginsky·M. Branchesi·J. E. Brau·T. Briant
View original source ↗Read source document ↗Export metadata ↓

Abstract

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the universe. We carry out a search for the stochastic background with the latest data from LIGO and Virgo. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Omega_GW(f)=Omega_alpha*(f/f_ref)^alpha, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of alpha=0, we constrain the energy density of the stochastic background to be Omega_GW(f)<5.6x10^-6. For the 600-1000 Hz band, Omega_GW(f)<0.14*(f/900 Hz)^3, a factor of 2.5 lower than the best previously reported upper limits. We find Omega_GW(f)<1.8x10^-4 using a spectral index of zero for 170-600 Hz and Omega_GW(f)<1.0*(f/1300 Hz)^3 for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Explore related subjects

gr-qcastro-ph.COastro-ph.HE

Keep this discovery

BibTeXRIS

The LIGO Scientific Collaboration, the Virgo Collaboration, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, C. Affeldt, M. Agathos, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, M. Andersen, R. Anderson, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. Areeda, S. M. Aston, P. Astone, P. Aufmuth, C. Aulbert, L. Austin, B. E. Aylott, S. Babak, P. T. Baker, G. Ballardin, S. W. Ballmer, J. C. Barayoga, M. Barbet, B. C. Barish, D. Barker, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, M. A. Barton, I. Bartos, R. Bassiri, A. Basti, J. C. Batch, J. Bauchrowitz, Th. S. Bauer, B. Behnke, M. Bejger, M. G. Beker, C. Belczynski, A. S. Bell, C. Bell, G. Bergmann, D. Bersanetti, A. Bertolini, J. Betzwieser, P. T. Beyersdorf, I. A. Bilenko, G. Billingsley, J. Birch, S. Biscans, M. Bitossi, M. A. Bizouard, E. Black, J. K. Blackburn, L. Blackburn, D. Blair, S. Bloemen, M. Blom, O. Bock, T. P. Bodiya, M. Boer, G. Bogaert, C. Bogan, C. Bond, F. Bondu, L. Bonelli, R. Bonnand, R. Bork, M. Born, V. Boschi, Sukanta Bose, L. Bosi, C. Bradaschia, P. R. Brady, V. B. Braginsky, M. Branchesi, J. E. Brau, T. Briant. 2014-06-17. Improved Upper Limits on the Stochastic Gravitational-Wave Background from 2009-2010 LIGO and Virgo Data. https://doi.org/10.1103/physrevlett.113.231101

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Electrovacuum Black Hole Uniqueness

We prove the black hole uniqueness conjecture in the axially symmetric, stationary, electrovacuum setting, subject to the refined asymptotic analysis of the associated singular harmonic maps, which includes an analyticity hypothesis at the axes. More precisely, it is shown that any asymptotically flat solution of the Einstein--Maxwell equations in this class, with more than one black hole horizon component is either: Majumdar--Papapetrou, up to a duality rotation, in which case all logarithmic angle defects vanish, or every finite axis rod logarithmic angle defect is strictly negative and hence every interaction force is strictly attractive. The proof extends the singular harmonic map method used for vacuum Kerr uniqueness in [18].

gr-qc↗
arXiv2026

Constraining Modified Mass-to-Horizon Cosmology Through Primordial Inflationary Observables

We investigate slow-roll inflation in a modified cosmological framework inspired by a generalized mass-to-horizon relation (MHR), $M=\gamma {c^2 L^n}/{G}$, where $n$ is a real parameter and $\gamma$ a dimensional constant. Using Padmanabhan's emergence paradigm, we derive the modified Friedmann equations for a flat FRW universe and analyze the dynamics of a canonical scalar field (inflaton) under the slow-roll approximation. We study the resulting inflationary phenomenology for power-law and Starobinsky potentials. For power-law potentials, the MHR modification fails to reconcile these models with current CMB constraints on $r$ and $n_s$. In contrast, Starobinsky inflation exhibits significant sensitivity to deviations from $n=1$. A perturbative analysis ($n=1+\Delta$) yields corrections to inflationary observables. We observe that the scalar power-spectrum normalization, under a fixed-Starobinsky prescription, imposes the stringent constraint $0.960 \lesssim n \lesssim 1.040$ for $N=60$ efolds. This is considerably tighter than spectral-index bounds. Our results establish inflation, particularly Starobinsky-like models, as a sensitive probe of generalized horizon thermodynamics and departures from standard MHR scaling.

gr-qc↗
arXiv2026

Improving the Sensitivity of Gravitational Wave Detection with Weighted Conformal Prediction

In the last decade, kilometre-scale interferometric gravitational-wave detectors have observed hundreds of compact binary mergers, the majority of which are binary black holes. However, the data are noise-dominated, and multiple independent search algorithms (pipelines) are used to enhance sensitivity and improve robustness. Rather than the standard approach of selecting the most significant pipeline output, we combine the outputs from all pipelines using a conformal prediction-based framework to provide statistically rigorous confidence estimates for candidate events. While combining pipelines improves sensitivity and ranking robustness, it requires a principled statistical framework that remains valid as data properties evolve across observing runs. A key challenge is distribution shifts between simulated datasets used for training and calibration and the real, unlabelled, observations used for testing, which can invalidate coverage guarantees and bias confidence estimates. In this work, we address this challenge by incorporating likelihood-ratio reweighting into our conformal prediction framework to account for covariate shift. Using mock datasets containing simulated signals, we demonstrate that weighted conformal prediction restores well-calibrated coverage under covariate shift and increases the confidence of events near the detection threshold, recovering true signals that would otherwise be missed.

gr-qc↗