Abstract
We study the emission of space-time waves produced by back-reaction effects during a collapse of a spherically symmetric universe with a time-dependent cosmological parameter, which is driven by a scalar field. As in a previous work, the final state avoids the final singularity due to the fact the co-moving relativistic observer never reaches the center, because the physical time evolution \(\mathrm{d}\tau =U_{0}\,\mathrm{d}x^0\), decelerates for a co-moving observer which falls with the collapse. The equation of state of the system depends on the rate of the collapse, but always is positive: \(0< \omega (p) < 0.25\).
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Notes
We can define the operator
$$\begin{aligned} \delta {\hat{x}}^{\alpha }(t,\vec {x}) = \frac{1}{(2\pi )^{3/2}} \int \mathrm{d}^3 k \, {\check{e}}^{\alpha } \left[ b_k \, {\hat{x}}_k(t,\vec {x}) + b^{\dagger }_k \, {\hat{x}}^*_k(t,\vec {x})\right] , \end{aligned}$$such that \(b^{\dagger }_k\) and \(b_k\) are the creation and destruction operators of space-time, such that \(\left\langle B \left| \left[ b_k,b^{\dagger }_{k'}\right] \right| B \right\rangle = \delta ^{(3)}(\vec {k}-\vec {k'})\) and \({\check{e}}^{\alpha }=\epsilon ^{\alpha }_{\,\,\,\,\beta \gamma \delta } {\check{e}}^{\beta } {\check{e}}^{\gamma }{\check{e}}^{\delta }\), where
in order to
We use the asymptotic expressions for the Bessel functions, for \(f(t) \gg 1\), which are
References
V. Husain, O. Winkler, Phys. Rev. D71, 104001 (2005)
R. Sharma, S. Das, R. Tikekar, Gen. Relativ. Gravit. 47, 25 (2015)
L. Herrera, N.O. Santos, Phys. Rev. D70, 084004 (2004)
Martin Bojowald, Rituparno Goswami, Roy Maartens, Parampreet Singh, Phys. Rev. Lett. 95, 091302 (2005)
Rituparno Goswami, Pankaj S. Joshi, Parampreet Singh, Phys. Rev. Lett. 96, 031302 (2006)
C. Gundlach, Living Rev. Relativ. 2, 4 (1999)
R. Goswami, P.S. Joshi, Phys. Rev. D65, 027502 (2004)
R. Giambo, Class. Quantum Gravity 22, 2295 (2005)
J.Mendoza Hernández, M. Bellini, C.Moreno González, Phys. Dark Universe 23, 100251 (2019)
R.F. Baierlein, D.H. Sharp, J.A. Wheeler, Phys. Rev. 126, 1864 (1962)
J.A. Wheeler, Adv. Ser. Astrophys. Cosmol. 3, 27 (1987)
J.W. York, Phys. Rev. Lett. 16, 1082 (1972)
G.W. Gibbons, S.W. Hawking, Phys. Rev. D10, 2752 (1977)
L.S. Ridao, M. Bellini, Phys. Lett. B751, 565 (2015)
L.S. Ridao, M. Bellini, Astrophys. Space Sci. 357, 94 (2015)
S.W. Hawking, G.F.R. Ellis, The Large Scale Structure of Space-Time. Cambridge Monographs on Mathematical Physics (Cambridge University Press, Cambridge, 1973)
A. Palatini. Deduzione invariantiva delle equazioni gravitazionali dal principio di Hamilton, Rend. Circ. Mat. Palermo 43: 203–212 (1919). [English translation by R. Hojman and C. Mukku in P.G. Bergmann and V. De Sabbata (eds.) Cosmology and Gravitation, Plenum Press, New York (1980)]
C. Rovelli, Living Rev. Relativ. 1, 1 (1998)
A. Ashtekar, J. Lewandowski, Class. Quantum Gravity 21, R53–R152 (2004)
Acknowledgements
This research was supported by the CONACyT-UDG Network Project No. 294625 “Agujeros Negros y Ondas Gravitatorias”. M. B. acknowledges CONICET, Argentina (PIP 11220150100072CO) and UNMdP (EXA852/18) for financial support.
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Hernández, J.M., Bellini, M. & Moreno, C. Space-time waves from a collapse with a time-dependent cosmological parameter. Eur. Phys. J. Plus 135, 207 (2020). https://doi.org/10.1140/epjp/s13360-020-00243-9
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DOI: https://doi.org/10.1140/epjp/s13360-020-00243-9