We consider a nonsingular origin for the universe starting from an Einstein static universe,
the so-called" emergent universe" scenario, in the framework of a theory which uses two …

We consider the effects of adding a scale-invariant R 2 term to the action of the scale-
invariant model (SIM) studied previously by one of us (Guendelman EI 1999 Mod. Phys. Lett …

A unified multiscalar field model with three flat regions is discussed. The three flat regions
are the inflation, early-and late dark energy epochs. The potential is obtained by a …

In this paper we investigate the trace anomaly in a space-time where single events are
delocalized as a consequence of short distance quantum coordinate fluctuations. We obtain …

We study in some detail the properties of a previously proposed new class of string and
brane models whose world-sheet (world-volume) actions are built with a modified …

We consider a scale invariant model which includes a R 2 term in action and show that a
stable``emerging universe''scenario is possible. The model belongs to the general class of …

A scale invariant model containing dilaton ϕ and dust (as a model of matter) is studied
where the shift symmetry ϕ→ ϕ+ const. is spontaneously broken at the classical level due to …

The dilaton-gravity sector of the two-measures field theory (TMT) is explored in detail in the
context of spatially flat Friedman-Robertson-Walker (FRW) cosmology. The model …

Scale invariant theories which contain maximal rank gauge field strengths (of D indices in D
dimensions) are studied. The integration of the equations of motion of these gauge fields …

There exist field theory models where the fermionic energy–momentum tensor contains a
term proportional to which may contribute to the dark energy. We show that this new field …