RT Journal Article T1 Imprint of ultralight vector fields on gravitational wave propagation A1 Delgado Miravet, Alfredo A1 López Maroto, Antonio AB We study the effects of ultralight vector field (ULVF) dark matter on gravitational wave propagation. We find that the coherent oscillations of the vector field induce an anisotropic suppression of the gravitational wave amplitude as compared to the standard cosmology prediction. The effect is enhanced for smaller vector field masses and peaks for modes around k = H-0/root a(H = m). The suppression is negligible for astrophysically generated gravitational waves but could be sizable for primordial gravity waves. We discuss the possibility of detecting such an effect on the tensor power spectrum with future cosmic microwave background B-mode polarization detectors. We find that for the sensitivity of the upcoming LiteBIRD mission, the correction to the tensor power spectrum at decoupling time could be distinguishable from that of ACDM for ULVF masses m less than or similar to 10(-26) eV and sufficiently large abundances. PB Amer Physical Soc SN 2470-0010 YR 2021 FD 2021-06-28 LK https://hdl.handle.net/20.500.14352/8416 UL https://hdl.handle.net/20.500.14352/8416 LA eng NO © 2021 American Physical SocietyThis work has been supported by the Ministerio de Economia y Empresa (MINECO) (Spain) Projects No. FIS2016-78859-P and No. PID2019-107394 GB-I00 (AEI/FEDER, UE). A. D. M. acknowledges financial support by the Ministerio de Ciencia, Innovacion y Universidades (MICIU) (Spain) through a Formacion de Profesorado Universitario Fellowship FPU18/04599.Ministerio de Ciencia, Innovacion y Universidades. NO Ministerio de Economía y Competitividad (MINECO)/AEI/FEDER NO Ministerio de Ciencia, Innovacion y Universidades (MICIU) DS Docta Complutense RD 6 abr 2025