Ripples in space-time from a pair of merging black holes have been recorded in unprecedented detail, enabling physicists to test predictions of general relativity

We develop the computational framework for gravitational wave - black hole scattering in worldline quantum field theory (WQFT) without spin. Crucially, we prove on general grounds that, in the absence of dissipation, the exponential representation of the $S$-matrix maps -- through a partial-wave transformation -- directly onto the scattering phase shift from black hole perturbation theory (BHPT), indicating an exponentiation of the WQFT amplitude itself in partial-wave space. Computing explicitly, we reproduce the BHPT phase shift without spin up to $O(G^{3})$ from WQFT. While this result is expected, it lays the groundwork for higher-precision analyses involving non-minimal effects. Along the way, we outline our efficient diagram generation technique and include a pedagogical discussion on the computation of the required two-loop integrals.

New Haven CT (SPX) Feb 08, 2026 - An international collaboration of astrophysicists that includes researchers from Yale has created and tested a detection system that uses gravitational waves to map out the locations of merging blac

Tidal interaction is a unique, detectable signature in gravitational wave signals from inspiraling binary neutron stars (BNSs), which can be used to constrain the neutron star (NS) equation of state (EoS). The tidal interaction is resonantly amplified as the orbital frequency approaches the NS fundamental mode (f-mode) frequency. It has been shown that the exclusion of tidal resonance in parameter estimation leads to a significant bias in the inferred NS tidal deformability and hence the NS EoS [Pratten et al. PRL 129, 081102 (2022)]. The strength and location of tidal resonance depend sensitively on the f-mode frequency, which is typically modeled using its universal relation with the tidal deformability that is derived for an isolated, non-spinning NS assuming only linear fluid perturbations. In a BNS inspiral, the f-mode frequency can be corrected by at least three known effects: nonlinear hydrodynamics, background spin, and relativity. We use Hamiltonian Monte Carlo simulations to estimate the systematic bias on tidal deformability when each frequency correction is ignored. Our study considers both loud, individual events and the stacking of a population of detections. Both scenarios are expected when the next-generation detectors are available with a sensitivity level increased by about an order of magnitude.

An international collaboration of astrophysicists that includes researchers from Yale has created and tested a detection system that uses gravitational waves to map out the locations of merging black holes—known as supermassive black hole binaries—around the universe. Such a map would provide a vital new way to explore and understand astronomy and physics, just as X-rays and radio waves did in earlier eras, the researchers say. The new protocol demonstrated by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) offers a detection protocol to populate the map.

The detection of a stochastic gravitational wave background by pulsar-timing arrays indicates the presence of a population of supermassive black hole binaries. Although the observed spectrum generally matches predictions for orbital evolution driven by gravitational-wave emission in circular orbits, there is a preference for a spectral turnover at the lowest observed frequencies, which may point to substantial hardening during a transition from early environmental influences to later stages dominated by emission. In the vicinity of these binaries, the ejection of stars or dark matter particles through gravitational three-body slingshots efficiently extracts orbital energy, leading to a low-frequency turnover in the spectrum. Here we model how the gravitational-wave spectrum depends on the initial inner galactic profile before scouring by binary ejections while accounting for a range of initial binary eccentricities. By analysing the NANOGrav 15-year data, we find that a parsec-scale galactic-centre density of around $10^6 M_{\odot} \mathrm{pc}^{-3}$ is favoured across most of the parameter space, thus shedding light on the environmental effects that shape black hole evolution and the combined matter density near galaxy centres.

The lowest-frequency gravitational wave background may be shaped by supermassive black hole binaries that scatter nearby stars or dark matter. In this case, the NANOGrav 15-year dataset favours dense galactic centres with 106 solar masses per cubic parsec.

This review article is based on a seminar presented at the Higgs pairs workshop 2025. Stochastic gravitational wave backgrounds can serve as probe of the diverse phenomenology encountered in beyond-Standard-Model scenarios featuring phase transitions in the early Universe. Focussing on gravitational wave production from first-order phase transitions, we present the main results of a recent analysis by the LISA Cosmology Working Group concerning the detectability of such signals with LISA. Strong degeneracies, both among the parameters controlling the phase transition and between these and the parameters of the beyond-Standard-Model scenario underlying the phase transition, complicate the reconstruction of the model from a potential signal. Nonetheless, once a specific scenario is assumed, LISA observations can supply constraints possibly complementary to those obtainable from present and future particle colliders.

Los Angeles CA (SPX) Feb 02, 2026 - When two neutron stars collide, they generate gravitational waves and light across the electromagnetic spectrum, from intense gamma ray flashes to faint radio signals that can persist for years. The

We present a systematic post-Newtonian treatment of binary charged black holes immersed in external magnetic fields within the framework of Einstein-Maxwell theory. By incorporating a uniform external magnetic field into the two-body Lagrangian expanded to first post-Newtonian order, we derive the complete equations of motion that capture both gravitational and electromagnetic interactions. The magnetic Lorentz force fundamentally alters the orbital dynamics, breaking the conservation of linear and angular momentum and inducing transitions from planar to three-dimensional trajectories. {Through numerical integration of these equations, we compute the resulting gravitational waveforms and characterize the distinctive magnetic field signatures through time-domain and frequency-domain analysis.} Our results demonstrate that strong background magnetic fields can substantially modify the orbital evolution and leave distinctive signatures in the gravitational wave signals. These findings provide a promising avenue for detecting charged black holes and probing magnetic field environments through gravitational wave observations.

The stochastic gravitational-wave background (SGWB), arising from the incoherent superposition of numerous compact binary coalescences, serves as a powerful probe of both astrophysical populations and fundamental physics. In this work, we investigate the influence of gravitational lensing on the SGWB, focusing on primordial black holes (PBHs) as potential lenses. Assuming PBHs as dark matter candidates with a broad cosmic distribution, we show that their lensing optical depth can be significantly enhanced, producing pronounced effects with relative deviations at the 10^-1 level. By systematically varying the PBH mass (M_PBH) and abundance (f_PBH), we demonstrate that the mass predominantly determines the frequency-dependent diffraction features of the spectrum, while the abundance primarily amplifies the overall lensing-induced deviation. Although the SGWB from binary black holes has not yet been observed, our analytical results provide theoretical insight into the possible imprint of lensing on its spectrum and suggest that future detections could offer a novel avenue to constrain dark matter scenarios.

"You are this body, and you are these molecules, and you are these atoms, and you are these quantum entities, and you are the quantum foam, and you are the energetic field of space-time, and, ultimately, you are the fundamental awareness out of which all these emerge."

Bitcoin bearish sentiments continue to dominate the market, after prices fell below the key $80,000 on January 31, resulting in a new wave of market liquidations. Interestingly, a pseudonymous analyst with the username CryptoMe has identified an “air pocket” in the present price structure, which potentially points to the downside target of this recent price drop. ## **Bitcoin Now Below $80K Support Zone – What Next?** In a QuickTake post on January 31, CryptoMe draws attention to an existing price vacuum between $73,000 – $80,000 as confirmed by three different market metrics. This observation is important in anticipating Bitcoin downside targets, considering the presently heightened market fears following the latest price decline. According to CryptoMe, liquidity levels on the Binance spot order book showed a concentration of limit buy orders between $73,000 – $80,000 that formed between late October and early November. Despite the price surge from $80,000 to around $100,000 seen in late Q4 2025, the liquidity cluster price zone remained untouched. Therefore, the zone is likely to act as a short-term price magnet should bearish momentum persist, as markets often gravitate toward areas of unfilled liquidity during periods of heightened volatility. Another on-chain metric that supports the existence of an air pocket between $73,000 – $80,000 is the Unspent Transaction Output (UTXO) price histogram. Each Bitcoin transaction consumes existing UTXOs and creates new ones; therefore, UTXOs are a good measure of on-chain transaction activity. As seen in the chart above, the sparse UTXO density between $73,000 and $80,000 suggests that a small number of transactions occurred within this price range. Thus, investors failed to establish a cost basis that would prevent further price decline, as prices have now slipped below $80,000. The final metric highlighted by CryptoMe is the Spot ETF Investor Average Cost, which currently stands at $79,000. Following the launch of the Bitcoin Spot ETFs in January 2024, Bitcoin has failed to trade below its realized price until now. Considering all three metrics, it’s likely that Bitcoin is headed for the $73,000 price mark, which the market has not visited since April 2025. Moreover, such a decline would represent a 40% devaluation from the present market all-time high. ## **Bitcoin Price Overview** At the time of writing, Bitcoin trades at $78,558, reflecting a 6.5% increase in the last 24 hours. Meanwhile, total trading volume is up by 37.15% and valued at $74.67 billion. Source: https://www.newsbtc.com/news/bitcoin/bitcoin-air-pocket-presents-potential-fall-to-73000-details/