We discuss low frequency radio astronomy from the moon, predominantly in the context of studying the neutral intergalactic medium during cosmic reionization using the HI 21cm line of neutral hydrogen. The epoch of reionization is the next frontier in observational cosmology, and HI 21cm studies are recognized as the most direct probe of this key epoch in cosmic structure formation. Current cons...

LIGO and Virgo have initiated the era of gravitational-wave (GW) astronomy; but in order to fully explore GW frequency spectrum, we must turn our attention innovative techniques for detection. One such approach is use binary systems as dynamical detectors by studying subtle perturbations their orbits caused impinging GWs. We present a powerful new formalism calculating orbital evolution generic...

Abstract Present understandings of accretion disks based on X-ray observations are reviewed. The main focus is observational properties around black holes in binaries and their phenomenological interpretations. Since there several excellent reviews hole already, we here pick up a limited number important works which introduced key clues widen and/or deepen the understanding disks, recalling his...