Dark Energy in a perturbed Weyl-Dirac Universe
  In the framework of Weyl-Dirac's theory a perturbed universe is considered. It contains luminous matter, dark matter consisting of weylons as well dark energy (DE) presented by Dirac's gauge function,\beta. A massive body creates a spherically symmetric gravitational field, that is regarded as the perturbation of the homogeneous and isotropic universe [20]. Around the perturbing mass the dark energy forms up a ball-like concentration that reaches the horizon. The energy-mass density of this DE ball, the pressure and mass are searched. It turns out that they all are negative. As negative pressure is necessary to get acceleration at the expanding phase and deceleration during contraction, the Weyl-Dirac DE is an appropriate candidate. The negative mass of the DE ball is universally repulsive, both positive-mass and negative-mass objects will be pushed away by the ball. The negative DE mass and the negative DE pressure can be regarded as causing and supporting the present cosmic acceleration. 
Mark Israelit
gr-qc