{"total":12,"items":[{"citing_arxiv_id":"2605.24715","ref_index":139,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Gravitational Waves from Post-Inflationary Magnetism: Direct and Scalar-Induced Contributions","primary_cat":"astro-ph.CO","submitted_at":"2026-05-23T20:01:09+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":4.0,"formal_verification":"none","one_line_summary":"In a post-inflationary magnetogenesis scenario with time-dependent gauge couplings, magnetic anisotropic stress dominates peak GW amplitude while scalar-induced terms matter on larger scales, both showing f^3 infrared scaling for blue spectra and potentially reaching PTA frequencies.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2605.05157","ref_index":64,"ref_count":2,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Are PTA measurements sensitive to gravitational wave non-Gaussianities?","primary_cat":"astro-ph.CO","submitted_at":"2026-05-06T17:28:29+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"PTA statistical tests cannot distinguish Gaussian and non-Gaussian GWB amplitude distributions in a model-agnostic way after decorrelation.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"frequencyf follows Poisson statistics with mean⟨N(f)⟩∝ fα, with α= −8/3for circular, GW-driven bina- ries [63, 64], and differentαfor more realistic population models including corrections such as environmental ef- fects and eccentricity [65-70]. The number of sources per frequency bin fluctuates according to Poisson statistics, so fluctuations inN/⟨N⟩directly translate into signal variance [64, 71]. Since we can only measure a single real- ization, we cannot measure this statistic without detailed knowledge of the underlying population [72]. Moreover, the signal amplitude is generically expected to have a distribution that can deviate from a Gaussian [73]. This is thenon-Gaussianitythat we hope to measure. Second, for a finite SMBH binary population, each"},{"citing_arxiv_id":"2604.21010","ref_index":37,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"Gravity Echoes from Supermassive Black Hole Binaries","primary_cat":"astro-ph.HE","submitted_at":"2026-04-22T19:00:04+00:00","verdict":"UNVERDICTED","verdict_confidence":"UNKNOWN","novelty_score":8.0,"formal_verification":"none","one_line_summary":"Future microhertz detections combined with nanohertz pulsar terms can serve as gravity echoes to measure supermassive black hole binary inspiral rates from hundreds to thousands of years in the past.","context_count":1,"top_context_role":"method","top_context_polarity":"use_method","context_text":"For the sources considered here,Λis large. For ex- ample, forq= 1andM tot = 10 9 M⊙ at Earth-term frequencyf E = 1µHz and a pulsar atL p = 1kpc givesΛ≈2000. Even a less massive, Typical source withM tot = 6×10 8 M⊙ yieldsΛ≈850. In this regime Eq. (10) reduces tosin 2(θopt/2) = 1/9, giving θopt = 2 arcsin(1/3)≈39 ◦, consistent with the peak in Fig. 2 calculated numerically with thegwent[37] and hasasia[31, 33] software packages. Counterintuitively, Eq. (9) and Figure 2 show that the most informative pulsars are not those closest to or farthest from the source on the sky, but those at interme- diate separations. Each pulsar withρ(θ)above threshold constrains the source to lie within an annular ring on the sky centered on that pulsar, while nondetections exclude"},{"citing_arxiv_id":"2604.20975","ref_index":43,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"Probing Supermassive Black Hole Mergers with Pulsar Timing Arrays","primary_cat":"astro-ph.HE","submitted_at":"2026-04-22T18:06:01+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":7.0,"formal_verification":"none","one_line_summary":"Pulsar timing arrays can probe supermassive black hole binaries that merged prior to observations via the pulsar term, with SKA potentially detecting a few such zombie binaries at SNR > 3.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"Gravitational Waves from Supermassive Black Hole Coa- lescence in a Hierarchical Galaxy Formation Model, ApJ 615, 19 (2004), arXiv:astro-ph/0404389 [astro-ph]. [42] A. Sesana, A. Vecchio, and C. N. Colacino, The stochastic gravitational-wave background from massive black hole binary systems: implications for observations with Pulsar Timing Arrays, MNRAS390, 192 (2008), arXiv:0804.4476 [astro-ph]. [43] S. Chen, A. Sesana, and C. J. Conselice, Constraining as- trophysical observables of galaxy and supermassive black hole binary mergers using pulsar timing arrays, MNRAS 488, 401 (2019), arXiv:1810.04184 [astro-ph.GA]. [44] Planck Collaborationet al., Planck 2018 results. VI. Cosmological parameters, A&A641, A6 (2020), arXiv:1807.06209 [astro-ph.CO]."},{"citing_arxiv_id":"2604.19701","ref_index":9,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"A practical theorem on gravitational-wave background statistics","primary_cat":"astro-ph.CO","submitted_at":"2026-04-21T17:20:51+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":7.0,"formal_verification":"none","one_line_summary":"For large but finite source counts, the PDF of rescaled GWB characteristic strain squared follows the universal form N^{1/3} times the reflected map-Airy distribution evaluated at N^{1/3}(y-1), fully determined by the mean strain and a new cubic shot-noise scale.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"c(f) falls below the idealized Gaus- sian power spectrum h2c(f) at high frequencies. It was later pointed out in Ref. [8] that the Poisson distribution of SMBHBs leads toanisotropiesin the GWB, with in- creased angular fluctuations at high frequencies, where the characteristic number of sources decreases. Such dis- creteness effects in the GWB are an important signa- ture of SMBHBs [9], allowing to discriminate between an astrophysical origin and more exotic sources of the nanohertz GWB [10]. At a fundamental level, finite-number effects lead to a non-Gaussian probability distribution function (PDF) of pulsar timing residuals [11, 12]. In practice, the exact computation of this PDF for a realistic number of pulsars is an intractable problem [13]."},{"citing_arxiv_id":"2604.08506","ref_index":57,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"The Heavy Tailed Non-Gaussianity of the Supermassive Black Hole Gravitational Wave Background","primary_cat":"astro-ph.CO","submitted_at":"2026-04-09T17:49:25+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"The gravitational wave background from supermassive black hole binaries has a universal heavy-tailed amplitude distribution with power-law index -4, causing divergent higher moments and dominance of the strongest signals by few loud sources.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2604.08373","ref_index":35,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"Stochastic problems in pulsar timing","primary_cat":"astro-ph.HE","submitted_at":"2026-04-09T15:35:35+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":5.0,"formal_verification":"none","one_line_summary":"Analytical solutions to Langevin equations for red noise and GWB in pulsars show that an Ornstein-Uhlenbeck spin frequency model is inconsistent with stationary signals, while an overdamped oscillator model and a two-component neutron star model resolve nonstationarity through damped and diffusive e","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"The reality condition onh ij(t, ⃗ x) imposes ˜hA∗(f, ˆΩ) = ˜hA(−f, ˆΩ). The quantityH(f) is the power spectrum of the GWB signal; we also choose that it sat- isfiesH(f) =H(−f). The statistics (17-19) and Isserlis' theorem [81] for the higher point functions and moments is consistent with a GWB that is produced by a very large number of individually irresolvable, weak GW sources [35]. Substituting (16) into (13), and performing the time integration, we obtain za(t) = Z ∞ −∞ d f Z S2 dˆΩ X A=+,× ˜hA(f, ˆΩ)F A a (ˆΩ) ×U a(f, ˆΩ)e−2πif[t+t E+Da] , (20) where the quantitiesF +/× a (ˆΩ) are so-called antenna pat- tern functions; F A a (ˆΩ) = ni anj aϵA ij(ˆΩ) 2 \u0010 1 + ˆna · ˆΩ \u0011 ,(21) and theU a(f, ˆΩ)'s are given by Ua(f, ˆΩ) = 1−e 2πif Da(1+ˆna·ˆΩ) ."},{"citing_arxiv_id":"2512.21392","ref_index":18,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Sensitivity of Weak Lensing Surveys to Gravitational Waves from Inspiraling Supermassive Black Hole Binaries","primary_cat":"astro-ph.CO","submitted_at":"2025-12-24T19:22:55+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":4.0,"formal_verification":"none","one_line_summary":"Weak lensing surveys cannot detect nanohertz-microhertz gravitational waves from supermassive black hole binaries under realistic conditions; only unattainable idealized surveys could probe this band.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2512.10795","ref_index":19,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Reaching diffraction-limited localization with coherent PTAs","primary_cat":"astro-ph.IM","submitted_at":"2025-12-11T16:41:44+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"Coherent map-making with pulsar distances in PTAs reaches diffraction-limited angular resolution of ~2 arcmin for GW sources at SNR=10 using roughly 9 pulsars.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2511.09659","ref_index":41,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Finite Populations & Finite Time: The Non-Gaussianity of a Gravitational Wave Background","primary_cat":"gr-qc","submitted_at":"2025-11-12T19:05:59+00:00","verdict":null,"verdict_confidence":null,"novelty_score":null,"formal_verification":null,"one_line_summary":null,"context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2510.04537","ref_index":68,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Finding Supermassive Black Hole Binary Mergers in Pulsar Timing Array Data","primary_cat":"astro-ph.HE","submitted_at":"2025-10-06T07:00:08+00:00","verdict":"CONDITIONAL","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"A complete SMBHB waveform model enables unified PTA searches for mergers and memory signals, with parameter recovery shown on simulated data for 10^8-10^10 solar mass systems.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2505.16820","ref_index":132,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Isotropy, anisotropies and non-Gaussianity in the scalar-induced gravitational-wave background: diagrammatic approach for primordial non-Gaussianity up to arbitrary order","primary_cat":"astro-ph.CO","submitted_at":"2025-05-22T15:55:50+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"Extends diagrammatic approach for scalar-induced gravitational waves to arbitrary-order local PNG, deriving semi-analytic spectra for energy density, anisotropies, bispectrum and trispectrum up to quartic terms.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"Figure 10: Energy-density fraction spectra of SIGWs in the present Universe compared with the sensitivity curves of Laser Interferometer Space Antenna (LISA) (blue shaded region) [122, 123, 176], Tianqin (orange shaded region) [127, 128, 177], Taiji (green shaded region) [124, 126], Deci-hertz Interferometer Gravitational wave Observatory (DECIGO) (red shaded region) [129, 130, 178], and Big Bang Observer (BBO) (purple shaded region) [131, 132, 178]. For all the cases,σ= 1 is assumed for the spectra. Tianqin possess the capability to detect SIGWs whenA S reaches 10−3, particularly in cases of positive PNG. Moreover, BBO and DECIGO exhibit higher sensitivity in detecting GWs, enabling them to detect SIGWs at smaller values ofA S. Notably, detectable SIGWs by these space-borne detectors may be accompanied by the production of PBHs, which could poten-"}],"limit":50,"offset":0}