B-mode of Gravitational Waves in preinflation with negative spatial curvature

MAURICIO BELLINI

PHYSICS OF THE DARK UNIVERSE

Elsevier Sciences

Lugar: Amsterdam; Año: 2023 vol. 40 p. 101222 - 101222

I study primordial gravitational waves in a preinflationary scenario with negative spatial curvature $K=-H^2_0$ and an initially null energy density. In this scenario the expansion is driven by a scalar (phantom) field with negative kinetic energy density and the cosmological parameter is given by the expectation value of the flow the field $hat{sigma}^{mu}$, $hat{sigma}$-being the geometric response to the quantum fluctuations of the phantom field. In this framework, the dynamics of gravitational waves components $hat{deltaPsi}_{ij}$ is studied and the $b$-polarization mode for gravitational waves is calculated. Finally, it is obtained the gravitational energy by unit time and transversal area, transported by each $k$-mode of the GW: $I(k,t)=|ec{{cal S}}(k,t)|$, related to the vector field: $ec{{cal S}}(k,t)= c,sqrt{g_{00}},left[ ec{u}(k,t) imes ec{v}(k,t)ight]$..