2025/11/24 by Xing-Yu Yang, Tan Chen, Yang, Xing-Yu +3 · 2 citations
Physics and Astronomy · #Pulsars and Gravitational Waves Research #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories
paper · pdf · doi:10.1103/6w3p-8ym2
We show that oscillating (real-scalar) boson stars generically host an oscillating radial caustic. Sources near this caustic cross it every half period, thereby producing periodic caustic-crossing lensing. The resulting observables are phase locked to the lens oscillation: image-pair creation or annihilation, changing image morphology, achromatic photometric spikes, and astrometric motion. This signal provides a distinctive target for time-domain astronomy, and its detection would reveal an intrinsically time-dependent compact dark-sector object. Event-number estimates indicate a measurable discovery space with current astrometric and high-cadence photometric surveys, while null searches would constrain the abundance of such objects as dark matter. The predictions rely only on the dynamics of real-scalar condensates and extend naturally to self-interacting real scalars, including axionlike particles, and to ultralight vector bosons.