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http://dx.doi.org/10.1103/physrevd.51.3450 | DOI Listing |
Sci Bull (Beijing)
January 2025
School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China; Center for High Energy Physics, Peking University, Beijing 100871, China; Key Laboratory of Particle Acceleration Physics and Technology, Chinese Academy of Sciences, Beijing 100049, China. Electronic address:
Dark photons, as a minimal extension of the Standard Model through an additional Abelian gauge group, may propagate relativistically across the galaxy, originating from dark matter decay or annihilation, thereby contributing to a galactic dark photon background. The generation of dark photons typically favors certain polarization modes, which are dependent on the interactions between dark matter and dark photons. We introduce a framework in which a resonant cavity is utilized to detect and differentiate these polarizations, leveraging the daily variation in expected signals due to the anisotropic distribution of dark photons and the rotation of the Earth.
View Article and Find Full Text PDFSpace Sci Rev
November 2024
Institute for Geochemistry and Petrology, ETH Zürich, 8092 Zurich, Switzerland.
We provide an overview of the isotopic signatures of presolar supernova grains, specifically focusing on Ti-containing grains with robustly inferred supernova origins and their implications for nucleosynthesis and mixing mechanisms in supernovae. Recent technique advancements have enabled the differentiation between radiogenic (from Ti decay) and nonradiogenic Ca excesses in presolar grains, made possible by enhanced spatial resolution of Ca-Ti isotope analyses with the Cameca NanoSIMS (Nano-scale Secondary Ion Mass Spectrometer) instrument. Within the context of presolar supernova grain data, we discuss () the production of Ti in supernovae and the impact of interstellar medium heterogeneities on the galactic chemical evolution of Ca/Ca, () the nucleosynthesis processes of neutron bursts and explosive H-burning in Type II supernovae, and () challenges in identifying the progenitor supernovae for Cr-rich presolar nanospinel grains.
View Article and Find Full Text PDFAstrobiology
October 2024
Space Research Institute, Austrian Academy of Sciences, Graz Austria.
In Lammer et al. (2024), we defined Earth-like habitats (EHs) as rocky exoplanets within the habitable zone of complex life (HZCL) on which Earth-like N-O-dominated atmospheres with minor amounts of CO can exist, and derived a formulation for estimating the maximum number of EHs in the galaxy given realistic probabilistic requirements that have to be met for an EH to evolve. In this study, we apply this formulation to the galactic disk by considering only requirements that are already scientifically quantifiable.
View Article and Find Full Text PDFBiomolecules
October 2024
School of Allied Health Sciences, Walailak University, Thasala 80161, Thailand.
The universe began 13.8 billion years ago, and Earth was born 4.6 billion years ago.
View Article and Find Full Text PDFPhys Rev Lett
October 2024
Racah Institute of Physics, The Hebrew University, 91904 Jerusalem, Israel.
Extreme mass ratio inspirals (EMRIs) occur when stellar-mass compact objects begin a gravitational wave (GW) driven inspiral into massive black holes. EMRI waveforms can precisely map the surrounding spacetime, making them a key target for future space-based GW interferometers such as LISA, but their event rates and parameters are massively uncertain. One of the largest uncertainties is the ratio of true EMRIs (which spend at least thousands of orbits in the LISA band) and direct plunges, which are in-band for at most a handful of orbits and are not detectable in practice.
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