A. Aguirre, Eternal In ation, past and future, in Beyond the Big Bang, Springer (2008).
 M. Kleban and M. Schillo, Spatial Curvature Falsi es Eternal In ation, JCAP 06 (2012) 029 [arXiv:1202.5037] [INSPIRE].
 A.H. Guth and Y. Nomura, What can the observation of nonzero curvature tell us?, Phys. Rev. D 86 (2012) 023534 [arXiv:1203.6876] [INSPIRE].
 B. Czech, M. Kleban, K. Larjo, T.S. Levi and K. Sigurdson, Polarizing Bubble Collisions, JCAP 12 (2010) 023 [arXiv:1006.0832] [INSPIRE].
 B. Freivogel, M. Kleban, M. Rodriguez Martinez and L. Susskind, Observational consequences of a landscape, JHEP 03 (2006) 039 [hep-th/0505232] [INSPIRE].
 R. Gobbetti and M. Kleban, Analyzing Cosmic Bubble Collisions, JCAP 05 (2012) 025 [arXiv:1201.6380] [INSPIRE].
 M. Kleban, T.S. Levi and K. Sigurdson, Observing the Multiverse with Cosmic Wakes, Phys. Rev. D 87 (2013) 041301(R) [arXiv:1109.3473] [INSPIRE]. [OpenAIRE]
 A. Aguirre, M.C. Johnson and A. Shomer, Towards observable signatures of other bubble universes, Phys. Rev. D 76 (2007) 063509 [arXiv:0704.3473] [INSPIRE].
 A. Aguirre and M.C. Johnson, Towards observable signatures of other bubble universes. II: Exact solutions for thin-wall bubble collisions, Phys. Rev. D 77 (2008) 123536 [arXiv:0712.3038] [INSPIRE].
 A. Aguirre, M.C. Johnson and M. Tysanner, Surviving the crash: assessing the aftermath of cosmic bubble collisions, Phys. Rev. D 79 (2009) 123514 [arXiv:0811.0866] [INSPIRE].
 M.C. Johnson and I.-S. Yang, Escaping the crunch: Gravitational e ects in classical transitions, Phys. Rev. D 82 (2010) 065023 [arXiv:1005.3506] [INSPIRE].
 M.C. Johnson, H.V. Peiris and L. Lehner, Determining the outcome of cosmic bubble collisions in full General Relativity, Phys. Rev. D 85 (2012) 083516 [arXiv:1112.4487] [INSPIRE].
 C.L. Wainwright, M.C. Johnson, H.V. Peiris, A. Aguirre, L. Lehner and S.L. Liebling, Simulating the universe(s): from cosmic bubble collisions to cosmological observables with numerical relativity, JCAP 03 (2014) 030 [arXiv:1312.1357] [INSPIRE].
 M.P. Salem, Bubble collisions and measures of the multiverse, JCAP 01 (2012) 021 [arXiv:1108.0040] [INSPIRE].
 R. Easther, J. Giblin, John T., L. Hui and E.A. Lim, A New Mechanism for Bubble Nucleation: Classical Transitions, Phys. Rev. D 80 (2009) 123519 [arXiv:0907.3234] [INSPIRE].