arxiv: 2508.20721 · v1 · ★pith:GV4NFEE7new · submitted 2025-08-28 · 🌀 gr-qc · astro-ph.CO· astro-ph.HE
Upper Limits on the Isotropic Gravitational-Wave Background from the first part of LIGO, Virgo, and KAGRA's fourth Observing Run
show 1767 more authors
read the original abstract
We present results from the search for an isotropic gravitational-wave background using Advanced LIGO and Advanced Virgo data from O1 through O4a, the first part of the fourth observing run. This background is the accumulated signal from unresolved sources throughout cosmic history and encodes information about the merger history of compact binaries throughout the Universe, as well as exotic physics and potentially primordial processes from the early cosmos. Our cross-correlation analysis reveals no statistically significant background signal, enabling us to constrain several theoretical scenarios. For compact binary coalescences which approximately follow a 2/3 power-law spectrum, we constrain the fractional energy density to $\Omega_{\rm GW}(25{\rm Hz})\leq 2.0\times 10^{-9}$ (95% cred.), a factor of 1.7 improvement over previous results. Scale-invariant backgrounds are constrained to $\Omega_{\rm GW}(25{\rm Hz})\leq 2.8\times 10^{-9}$, representing a 2.1x sensitivity gain. We also place new limits on gravity theories predicting non-standard polarization modes and confirm that terrestrial magnetic noise sources remain below detection threshold. Combining these spectral limits with population models for GWTC-4, the latest gravitational-wave event catalog, we find our constraints remain above predicted merger backgrounds but are approaching detectability. The joint analysis combining the background limits shown here with the GWTC-4 catalog enables improved inference of the binary black hole merger rate evolution across cosmic time. Employing GWTC-4 inference results and standard modeling choices, we estimate that the total background arising from compact binary coalescences is $\Omega_{\rm CBC}(25{\rm Hz})={0.9^{+1.1}_{-0.5}\times 10^{-9}}$ at 90% confidence, where the largest contribution is due to binary black holes only, $\Omega_{\rm BBH}(25{\rm Hz})=0.8^{+1.1}_{-0.5}\times 10^{-9}$.
This paper has not been read by Pith yet.
Forward citations
Cited by 14 Pith papers
Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.
-
Detecting Parity-Violating Gravitational Wave Backgrounds with Pulsar Polarization Arrays
gr-qc 2025-11 unverdicted novelty 7.0
Cross-correlating pulsar timing and polarimetry isolates the circular polarization of isotropic stochastic GW backgrounds and shares the Hellings-Downs angular pattern.
-
The First Upper Bound on the Non-Stationary Gravitational Wave Background and its Implication on the High Redshift Binary Black Hole Merger Rate
astro-ph.HE 2025-11 unverdicted novelty 7.0
First spectral covariance analysis of SGWB data yields upper bounds on non-stationary correlations that translate into mass-dependent limits on high-redshift PBH merger rates.
-
Joint population and strong-lensing inference for resolved gravitational-wave events probes the black-hole merger rate beyond the peak of star formation
astro-ph.HE 2026-06 unverdicted novelty 6.0
Joint strong-lensing and population inference on resolved gravitational-wave events finds no lensed events and tightens constraints on the black-hole merger rate peak redshift and high-redshift tail.
-
A thorough investigation of cross-correlation estimators for stochastic gravitational-wave background searches in ground-based detector data
gr-qc 2026-06 unverdicted novelty 6.0
Reformulation of frequency-domain narrowband cross-correlation estimators for SGWB searches provides new expressions for estimators and covariances, while showing that widely used prior expressions still yield correct...
-
Prospects for multi-messenger discovery of the gravitational-wave background anisotropies via cross-correlation with galaxies
astro-ph.CO 2026-05 unverdicted novelty 6.0
New simulations show that cross-correlating gravitational wave background anisotropies with galaxy distributions can enable discovery at angular scales of 4-6 degrees with next-generation observatories.
-
Universal Suppression of Gravitational Waves from Black Hole Evaporation Dynamics
astro-ph.CO 2026-06 unverdicted novelty 5.0
Black hole populations with finite-width mass distributions exhibit universal late-time evaporation-driven evolution that produces characteristic power-law suppression of induced gravitational waves, directly linking ...
-
Constraints on primordial black holes from the first part of LIGO-Virgo-KAGRA fourth observing run
astro-ph.CO 2026-05 unverdicted novelty 5.0
LIGO-Virgo-KAGRA O4a data yields the strongest constraints on primordial black hole abundance for 0.6-100 solar masses, with resolvable mergers dominating the limits and no compelling evidence for a PBH contribution i...
-
Stochastic modes in postquantum classical gravity
hep-th 2026-05 unverdicted novelty 5.0
Postquantum classical gravity requires stochastic spacetime fluctuations consisting of a diffusing spin-2 field and spin-0 scalar whose noise is constrained by LISA Pathfinder and decoherence bounds.
-
Measuring gravitational wave spectrum from electroweak phase transition and Higgs self-couplings
hep-ph 2025-11 unverdicted novelty 5.0
Frequency-domain simulations of the Taiji mission, including noise and foregrounds, demonstrate that the stochastic gravitational wave background from an electroweak phase transition can constrain Higgs cubic and quar...
-
Inflationary interpretation of the gravitational-wave signal in the European Pulsar Timing Array DR2 with constraints
astro-ph.CO 2026-06 unverdicted novelty 4.0
Constrains inflationary tensor parameters to fit the EPTA DR2 signal under CMB, BBN and LVK bounds, favoring radiation-era horizon re-entry but requiring low reheating temperatures.
-
Effects of formation channels and gravitational lensing on stochastic gravitational wave background
gr-qc 2026-05 unverdicted novelty 4.0
Using HBI on GWTC-4 data the authors compute lensed SGWBs for ABHs and PBHs and conclude that LIGO and ET can distinguish the two formation channels in specific frequency ranges, with ET offering broader coverage.
-
Testing cosmological isotropy with gravitational waves and gamma-ray bursts
astro-ph.CO 2026-04 unverdicted novelty 4.0
No significant cosmological anisotropy is found in the latest GW O4a and GRBWeb datasets using angular power spectra and two-point correlation functions, consistent with the cosmological principle.
-
Orientation matters: Consequences for gravitational-wave background detectability
gr-qc 2026-06 unverdicted novelty 3.0
Relative orientation of L-shaped interferometers drastically impacts detectability of isotropic and anisotropic gravitational-wave backgrounds in cross-correlation searches.
-
Bayesian analysis of the complex singlet model with phase transition gravitational waves
hep-ph 2025-11 unverdicted novelty 3.0
Bayesian forecasts for the Taiji detector constrain complex singlet model parameters through electroweak phase transition gravitational wave signals.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.