Macroscopic Dark Matter under siege: from White Dwarf Data to Gravitational Wave Detection

TL;DR

This work tightens the multi-messenger constraints on macroscopic Fermi-ball dark matter by integrating refined white-dwarf ignition physics and envelope structure with gravitational-wave detector signatures. The authors derive sub-saturated Fermi-ball profiles and scaling relations, update WD/NS ignition constraints, and show that space-based GW observatories like LISA and TianQin can detect or constrain Fermi-ball DM via a Doppler signal in the detector test masses. Their results demonstrate that WD-based bounds, together with GW observations and Fisher-matrix forecasts, place strong, complementary limits on Fermi-ball parameter space, enabling precise recovery of DM mass and distance in favorable cases. Overall, the paper advances a robust, multi-messenger pathway to test a broad class of macroscopic DM candidates in the coming decade.

Abstract

The nature of dark matter (DM) remains a profound mystery. Macroscopic candidates, such as Fermi-balls, offer a distinct alternative to conventional particle DM, yet their low number density makes terrestrial detection challenging. In this work, we present a unified search strategy for sub-saturated Fermi-ball DM. We first revisit and significantly update astrophysical constraints from compact objects, utilizing rigorous expressions and additional white dwarf data related to ignition and subsequent supernovae. Crucially, we then explore novel signatures of Fermi-balls in future gravitational wave experiments like LISA and TianQin, performing detailed signal-to-noise ratio and Fisher matrix analyses. By combining these updated white dwarf/neutron star limits with the projected gravitational wave sensitivities, we derive the most comprehensive constraints on Fermi-ball parameter space to date, demonstrating the power of multi-messenger approaches for probing macroscopic DM.

Figures (9)

• Figure 1: WD and NS constraints on Fermi-ball DM. The blue solid line represents the constraint with only gravitational interaction, and the dashed line represents the constraint with extra Yukawa attraction. The gray line represents the CMB constraints Jacobs:2014ycaDvorkin:2013cea.
• Figure 1: DM radius versus $N_X$ for $\alpha_X = 10^{-4}$.
• Figure 2: The signal PSD (dashed lines) of Fermi-ball DM on the GW detectors in the X channel and the corresponding noise PSD (solid lines).
• Figure 2: Expected number of DM passes through the detectors and impact factor of Fermi-ball DM as functions of DM mass in the X channel.
• Figure 3: Projected sensitivity of GW detectors to Fermi-ball DM with updated astrophysical constraints. The brown line and the gray line denote the constraints from NS kinetic heating and CMB, respectively.