Aug 2026· Monthly notices of the Royal Astronomical Society· Vol 551· 0 citations
Abstract
Ultralight dark matter (ULDM) can induce a slow frequency modulation of nearly monochromatic millihertz gravitational waves (GWs). Existing forecasts infer the carrier phase evolution from the GW data, leaving the modulation partially degenerate with the binary frequency derivatives. We incorporate the electromagnetic (EM) timing ephemeris of J0806/HM Cnc into a Fisher forecast. The X-ray and optical pulsations of this accreting ultracompact binary track its orbital phase, allowing the measured ephemeris to constrain the carrier phase evolution without directly constraining ULDM. At low ULDM masses, the modulation varies slowly over the observation and is partly absorbed by the timing polynomial in a GW-only analysis. The EM ephemeris reduces this degeneracy after marginalization. The projected inverse coupling reach improves by up to about two orders of magnitude for a direct linear coupling and by about one order of magnitude for a direct quadratic coupling. These are relative improvements for the same source and dark matter density. EM timing can therefore improve the sensitivity of future space-based GW searches to ULDM-induced modulation in verification binaries.
The pHz to sub-nHz GW regime remains largely unexplored but is crucial for mapping the early inspiral stage of SMBHBs and probing early-Universe physics. Astrometry and pulsar timing offer orthogonal and deeply complementary secular observables to investigate this frequency band. We aim to present the first joint data...
L. Filipello, William Beordo, V. Akhmetov et al.· 0 citations
Binary black holes (BBHs) formed in dense stellar environments or in hierarchical triples can coalesce on eccentric orbits and carry spins of arbitrary orientation, leaving distinctive imprints on their gravitational-wave (GW) emission. We present SEOBNRv6EPHM: the first generic-orbit, spin-precessing model in the effe...
A. Gamboa, L. Pompili, A. Buonanno et al.· 1 citation
Axion-like dark matter (ALDM) is a well-motivated dark matter candidate whose Chern-Simons coupling to photons can induce cosmic birefringence, producing temporal oscillations and spatial correlation in polarization angle (PA) signals from different sources. Hyperactive repeating fast radio bursts (FRBs) with high line...
Xiao-Hui Liu, Zi-Yan Yuwen, Yun-Long Zhang et al.· 0 citations
Dark matter substructure properties such as their mass function and spatial distribution depend on the nature of dark matter and are strong tests of the cosmological model. Like luminous matter, these dark matter substructures cause gravitational lensing affecting observables such as time delays. Given the millisecond-...
Gravitational-wave (GW) observations offer a powerful probe of new fundamental fields. One well-motivated source is black hole (BH)--boson cloud systems, in which an ultralight scalar field forms a cloud around a rotating BH via superradiance and emits long-lived nearly monochromatic GWs. In this work, we compute the s...
The lack of signals in direct detection experiments has placed the canonical Weakly Interacting Massive Particle (WIMP) paradigm under severe tension, motivating a shift toward the sub-GeV Light Dark Matter (LDM) regime. However, realizing detectable LDM interaction rates typically requires large couplings to the visib...
