Radiative Poincare type eon and its follower

Abstract

We consider two consecutive eons $\hat{M}$ and $\check{M}$ from Penrose's Conformal Cyclic Cosmology and study how the matter content of the past eon ($\hat{M}$) determines the matter content of the present eon ($\check{M}$) by means of the reciprocity hypothesis. We assume that the only matter content in the final stages of the past eon is a spherical wave described by Einstein's equations with the pure radiation energy momentum tensor $${\hat{T}}^{ij}=\hat{\Phi }{K}^i{K}^j,{\hat{g}}_{ij}{K}^i{K}^j=0,$$ and with cosmological constant $\hat{\Lambda }$ . We solve these Einstein's equations associating to $\hat{M}$ the metric $\hat{g}=t^{-2}(-d{t}^2+h_t)$, which is a Lorentzian analog of the Poincaré-Einstein metric known from the theory of conformal invariants. The solution is obtained under the assumption that the 3-dimensional conformal structure $[h]$ on the ${\mathcal{I}}^{+}$ of $\hat{M}$ is flat, that the metric $\hat{g}$ admits a power series expansion in the time variable $t$, and that $h_0\in [h]$. Such solution depends on one real arbitrary function of the radial variable $r$. Applying the reciprocal hypothesis, $\hat{g}\to \check{g}=t^4\hat{g}$, we show that the new eon $(\check{M},\check{g})$ created from the one containing a single spherical wave, is filled at its initial state with three types of radiation: (i) the damped spherical wave which continues its life from the previous eon, (ii) the in-going spherical wave obtained as a result of a collision of the wave from the past eon with the Bang hypersurface and (3) randomly scattered waves that could be interpreted as perfect fluid with the energy density $\check{\rho }$ and the isotropic pressure $\check{p}$ such that $\check{p}=\frac{1}{3}\check{\rho }$.

In ver 2, a remark about the convergence of the power series was added. Also some styllistic changes were made