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キーワード:
High Energy Physics - Theory, hep-th,General Relativity and Quantum Cosmology, gr-qc
要旨:
We perform a detailed study of the existence and the properties of
O(4)-invariant instanton solutions in Einstein-scalar theory in the presence of
flat potential barriers, i.e. barriers where the second derivative of the
potential is small at the top of the barrier. We find a whole zoo of solutions:
Hawking-Moss, Coleman-De Luccia (CdL), oscillating instantons, asymmetric CdL
as well as other non-standard CdL-like solutions with additional negative modes
in their spectrum of fluctuations. Our work shows how these different branches
of solutions are connected to each other via "critical" instantons possessing
an extra zero mode fluctuation. Overall, the space of finite action euclidean
solutions to these theories with flat barriers is surprisingly rich and
intricate.
