Naked-Eye Observable Microlensing Events

Abstract

We study the naked-eye observability of microlensing events for both known stars and possible massive compact halo objects (MACHOs). We nd that if both the dark matter disc and halo are composed of MACHOs in the Jupiter-mass range, microlensing events of naked-eye stars, undergoing at least one magnitude of magni cation occur at the rate of 1 per 2400 years, and have durations of from hours to days; we may thus surmise that the chance of at least one event occurring in the era of recorded history (the last 5,000 years) would be 1 ? e ?2:1 88%. For magni cation by known stars, we expect events at the rate of one per 40,000 years, so we should not be surprised not to have witnessed an event in the last 5000 years. However, in the last 200,000 years, while humans have inhabited the Earth, we expect of order 5 events, and thus a 99% chance that at least one observable event has occurred.

A critical review of classical bouncing cosmologies

“…In support of this claim, the PLANCK collaboration [425] team published results stating that the polarized thermal emission from Galactic dust is the main foreground present in measurements of the polarization of the CMBR at frequencies above 100 GHz. Colley and Gott [426] analyzed the genus topology of the BICEP2 B-modes in the BICEP2 region from the publicly available Q and U at 353 GHz preliminary PLANCK polarization maps and concluded that they have a primordial origin. This debate is ongoing, but should be resolved once the additional data from the future Keck Array observations at 100 GHz and PLANCK observations at higher frequencies become available.…”

Inflationary universe from perfect fluid andF(R)gravity and its comparison with observational data

“…Recently, there have also appeared the progresses to ensure the BICEP2 statements in Ref. [32]. It is also remarked that the representation of α s is also given in Ref.…”

Axion landscape and natural inflation

“…9 The tadpole condition is another important issue for implementing the KNP mechanism in the string theory, which requires a number of (brane) charges through the alignment of wrapping numbers of branes or gauge fluxes on branes in the extra dimensions, while the net charge of branes should be vanishing in the compact extra dimension. 10 In this respect, it is interesting to consider a possibility that the inflaton consists of RR two-form axions in type IIB model [42,44,45,47] and fluxed seven branes, which produce non-perturbative inflaton potential, are wrapping on a curved extra dimension with orientifolds. In this case, a tight consistency condition on three brane charges can be relaxed by the curvature corrections due to the seven branes [79,80].…”