A symmetry for vanishing cosmological constant

TL;DR

This paper explores two realizations of a symmetry principle in extra-dimensional models that enforce a zero cosmological constant and restrict the dimensionality, offering promising avenues for quantization and brane cosmology.

Contribution

It introduces two novel symmetry realizations that impose a zero cosmological constant and restrict dimensions, with implications for quantization and brane cosmology.

Findings

Symmetry requires dimensions D=2(2n+1).

Forbids a bulk cosmological constant.

Allows simple zero brane cosmological constant adjustment.

Abstract

Two different realizations of a symmetry principle that impose a zero cosmological constant in an extra-dimensional set-up are studied. The symmetry is identified by multiplication of the metric by minus one. In the first realization of the symmetry this is provided by a symmetry transformation that multiplies the coordinates by the imaginary number i. In the second realization this is accomplished by a symmetry transformation that multiplies the metric tensor by minus one. In both realizations of the symmetry the requirement of the invariance of the gravitational action under the symmetry selects out the dimensions given by D = 2(2n+1), n=0,1,2,... and forbids a bulk cosmological constant. Another attractive aspect of the symmetry is that it seems to be more promising for quantization when compared to the usual scale symmetry. The second realization of the symmetry is more attractive in that it is posible to make a possible brane cosmological constant zero in a simple way by using the same symmetry, and the symmetry may be identified by reflection symmetry in extra dimensions.