**110**(2015) 40008

## Solution to the cosmological-constant problem in a Regge quantum gravity model

^{1} Departamento de Matemática, Universidade Lusófona de Humanidades e Tecnologias Av. do Campo Grande, 376, 1749-024 Lisboa, Portugal ^{2} Grupo de Fisica Matemática da Universidade de Lisboa - Av. Prof. Gama Pinto, 2, 1649-003 Lisboa, Portugal

^{(a)} amikovic@ulusofona.pt^{(b)} vmarko@ipb.ac.rs

Received: 21 January 2015

Accepted: 20 May 2015

We show that it is possible to solve the cosmological constant (CC) problem in a discrete quantum gravity theory based on Regge calculus by using the effective action approach and a special path-integral measure. The effective cosmological constant is given as a sum of 3 terms: the classical CC, the quantum gravity CC and the matter CC. Since the observations can only measure the sum of these 3 terms, we can choose the classical CC to be equal to the negative value of the matter CC. Hence the effective CC is given only by the quantum gravity CC, which is determined by the path-integral measure. Since the path-integral measure depends on a free parameter, this parameter can be chosen such that the effective CC gives the observed value.

PACS: 04.60.Pp – Loop quantum gravity, quantum geometry, spin foams / 04.60.Gw – Covariant and sum-over-histories quantization / 04.62.+v – Quantum fields in curved spacetime

*© EPLA, 2015*