Space–times With Integrable Singularity: Black–white Holes and Astrogenic Universes

Abstract

We briefly review the problem of generating cosmological flows of matter in GR (the genesis of universes), analyze models' shortcomings and their basic assumptions yet to be justified in physical cosmology. We propose a paradigm of cosmogenesis based on the class of spherically symmetric solutions with integrable singularity r = 0. They allow for geodesically complete geometries of black/white holes, which may comprise space-time regions with properties of cosmological flows. * Astrospace Centre of the Levedev Physical Institute.

Consistent null-energy-condition violation: Towards creating a universe in the laboratory

“…Both zero energy solutions have Z = 0, so an interpolating configuration has Z ′ < 0 somewhere in between, and thus it is not ghost-free. One way to get around this obstacle would be to insist on slow spatial variation of the initial field configuration but give up the prescription that the field inside the large sphere is in the rolling regime (19). Instead, one would consider the field with non-zero energy density inside the sphere, so that there exists a smooth and ghost-free configuration that interpolates, as r increases, between this field and the asymptotic Minkowski vacuum.…”

“…This can be the case if there is another field, call it ϕ, which determines the couplings entering these functions, and this field acts as quasi-homogeneous background, ϕ = ϕ(x). In this case one can consider a field configuration π(t, x) which at any point in space is approximately given by the rolling solution (19), but with Y * depending on x (recall that Y * is independent of time for the homogeneous solution). We prepare the background ϕ(x) in such a way that Y * (x) is constant inside the large sphere (to evolve into a man-made universe) and gradually aproaches zero as r → ∞.…”

“…where we allow the parameter t * in (19) to vary in space, and choose a convenient parametrization. We choose t * (r) = t * ,in inside a somewhat smaller sphere of radius R 1 < R (but R 1 ∼ R) and t * (r) = t * ,out ≫ t * ,in at r > R 1 (hereafter subscripts in and out refer to the regions r < R 1 and r > R 1 , respectively), as shown in Fig.…”

“…[5,6]). Widely discussed ways out are to invoke tunneling [7,8,9,10,11,12,13,14,15,16] or other quantum effects [17,18,19], modify gravity [20,21,22] and violate NEC [23,24,25,26]. The latter option, however, has been problematic, since most of the NEC-violating theories are plagued by pathologies like ghosts, gradient instability and/or superluminality.…”

CPTM symmetry, closed time paths and cosmological constant problem in the formalism of extended manifold

“…with m i as some coefficients of the expansion, see [61][62][63][64][65][66][67] for the similar examples. Now, we require that the mass will continuously change the sign under the r → −r transform and therefore will require instead Eq.…”