Running of Newton's constant and noninteger powers of the d'Alembertian

LOPEZ NACIR, DIANA; FRANCISCO D. MAZZITELLI

PHYSICAL REVIEW D - PARTICLE AND FILDS

APS

Lugar: New York; Año: 2007 vol. 75 p. 24003 - 24015

0556-2821

The running of Newton´s constant can be taken into account by considering covariant, nonlocal generalizations of the field equations of general relativity. These generalizations involve nonanalytic functions of the d´Alembertian, as (-[larger open square])-alpha, with alpha a noninteger number, and ln[-[larger open square]]. In this paper we define these nonlocal operators in terms of the usual two point function of a massive field. We analyze some of their properties, and present specific calculations in flat and Robertson Walker spacetimes.