Primordial Gravitational Waves Spectrum in the Coupled-Scalar-Tachyon Bounce Universe. (arXiv:1901.06423v1 [gr-qc])

<a href="http://arxiv.org/find/gr-qc/1/au:+Zhang_N/0/1/0/all/0/1">Nan Zhang</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Cheung_Y/0/1/0/all/0/1">Yeuk-Kwan E. Cheung</a>

We derive in detail the equations of motion for the tensorial modes of

primordial metric perturbations in the Coupled-Scalar-Tachyon Bounce Universe.

We solve for the gravitational wave equations in the pre-bounce contraction and

the post-bounce expansion epochs. To match the solutions of the tensor

perturbations, we idealise the bounce process yet retaining the essential

physical properties of the bounce universe. We put forward two matching

conditions: one ensures the continuity of the gravitational wave functions and

the other respects the symmetric nature of the bounce dynamics. The matching

conditions connect the two independent modes of gravitational waves solutions

before and after the bounce. We further analyse the scale dependence and time

dependence of the gravitational waves spectra in the bounce universe and

compare them with the primordial spectrum in the single field inflation

scenario. We discuss the implications to early universe physics and present

model independent observational signatures extracted from the bounce universe.

We derive in detail the equations of motion for the tensorial modes of

primordial metric perturbations in the Coupled-Scalar-Tachyon Bounce Universe.

We solve for the gravitational wave equations in the pre-bounce contraction and

the post-bounce expansion epochs. To match the solutions of the tensor

perturbations, we idealise the bounce process yet retaining the essential

physical properties of the bounce universe. We put forward two matching

conditions: one ensures the continuity of the gravitational wave functions and

the other respects the symmetric nature of the bounce dynamics. The matching

conditions connect the two independent modes of gravitational waves solutions

before and after the bounce. We further analyse the scale dependence and time

dependence of the gravitational waves spectra in the bounce universe and

compare them with the primordial spectrum in the single field inflation

scenario. We discuss the implications to early universe physics and present

model independent observational signatures extracted from the bounce universe.

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