Description
According to general relativity, gravitational waves (GWs) should travel at the speed of light. However, different theories beyond General Relativity predict possible deviations from the speed of light, and some even introduce dispersion effects $ E^2 = p^2 + \mathbb{A}_\alpha p^\alpha $, where $\alpha = 0$ corresponds to the case where the graviton has mass $\mathbb{A}_0=m_g^2$. Comparing the waveforms from compact star mergers with theoretical waveforms can constrain dispersion parameters.We simulate the waveform of an supermassive black hole binary (SMBHB) merger across three different source catalogs, namely, PopIII, Q3-nod and Q3-d, detectable by LISA and employ Bayesian inference to constrain the coefficientc $\mathbb{A}_\alpha$ based on the simulated data. Considering a 5-year LISA observation period, the resulting constraints on the graviton mass were $ 2.1, 1.3, $ and
$ 0.4\times10^{-26} \, \mathrm{eV}/c^2 $ for each catalog, respectively. These results are especially sensitive to sources with high signal-to-noise ratios, meaning that LISA's detection time could increase by an order of magnitude, improving the constraints by two orders of magnitude. Additionally, this approach is applicable across a range of $\alpha$ values, from 0 to 4. Since SMBHB mergers generate electromagnetic signals, which are most likely to be detected in the X-ray band, we calculated their luminosity and found that, over five years, the number of sources that could be jointly observed by LISA and the X-ray telescopes eXTP, Athena, and AXIS would be 0–1, 1–8, and 1–10, respectively. These detections could constrain the gravitational wave speed deviation $\Delta c/c$ to $3\times10^{-16}-10^{-15}$, $3\times10^{-16}-2\times10^{-15}$, and $10^{-14}-10^{-13}$, corresponding to graviton mass constraints of $10^{-27}-10^{-25} \mathrm{eV}/c^2$.
| Talk category | NOVA Network 3 |
|---|---|
| Preference for a talk or poster | Poster |
| Talk preference for PhD students | Second-year PhD student in an integrated master's and doctoral program |
