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Cyclic completion of the anamorphic universe
Anna Ijjas
Cyclic models of the universe have the advantage of avoiding initial conditions problems related to postulating any sort of beginning in time. To date, the only known viable exampl…
Fully stable cosmological solutions with a non-singular classical bounce
Anna Ijjas, Paul J. Steinhardt
We recently showed how it is possible to use a cubic Galileon action to construct classical cosmological solutions that enter a contracting null energy condition (NEC) violating ph…
Classically stable non-singular cosmological bounces
Anna Ijjas, Paul J. Steinhardt
One of the fundamental questions of theoretical cosmology is whether the universe can undergo a non-singular bounce, i.e., smoothly transit from a period of contraction to a period…
NEC violation in mimetic cosmology revisited
Anna Ijjas, Justin Ripley, Paul J. Steinhardt
In the context of Einstein gravity, if the null energy condition (NEC) is satisfied, the energy density in expanding space-times always decreases while in contracting space-times t…