Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2010-09-14

Journal: MODERN PHYSICS LETTERS A

Included Journals: Scopus、SCIE

Volume: 25

Issue: 28

Page Number: 2431-2445

ISSN: 0217-7323

Key Words: Hawking radiation; greybody factor; cosmological constant

Abstract: We study the absorption and scattering of massless scalar waves propagating in spherically symmetric spacetimes with dynamical cosmological constant both in low-energy and high-energy zones. In the former low-energy regime, we solve analytically the Regge-Wheeler wave equation and obtain an analytic absorption probability expression which varies with M root Lambda, where M is the central mass and Lambda is cosmological constant. The low-energy absorption probability, which is in the range of [0, 0.986701], increases monotonically with increase in Lambda. In the latter high-energy regime, the scalar particles adopt their geometric optics limit value. The trajectory equation with effective potential emerges and the analytic high-energy greybody factor, which is relevant with the area of classically accessible regime, also increases monotonically with increase in Lambda, as long Lambda is less than or of the order of 10(4). In this high-energy case, the null cosmological constant result reduces to the Schwarzschild value 27 pi r(g)(2)/4.