Observational consequences of a landscape

By Ben Freivogel, Matthew Kleban, M. R. Martínez, L. Susskind. 2005

284 citations recorded by the source corpus.

In this paper we consider the implications of the ``landscape paradigm [1], [2] for the large scale properties of the universe. The most direct implication of a rich landscape is that our local universe was born in a tunnelling event from a neighboring vacuum. This would imply that we live in an open FRW universe with negative spatial curvature. We argue that the ``overshoot problem, which in other settings would make it difficult to achieve slow roll inflation, actually favors such a cosmology. We consider anthropic bounds on the value of the curvature and on the parameters of inflation. When supplemented by statistical arguments these bounds suggest that the number of inflationary efolds is not very much larger than the observed lower bound. Although not statistically favored, the likelihood that the number of efolds is close to the bound set by observations is not negligible. The possible signatures of such a low number of efolds are briefly described.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/c20632267356e6f172f8438800f3ba2e3acf3aa5

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Andrei Linde
2. Liam McAllister
3. D. Baumann
4. E. Pajer
5. L. Sorbo
6. Marco Peloso
7. G. Efstathiou
8. A. Guth

In Nuclear and High Energy Physics

1. Andrei Linde
2. Liam McAllister
3. D. Baumann
4. E. Pajer
5. L. Sorbo
6. G. Efstathiou
7. Marco Peloso
8. Eran Palti

Citations in the corpus

• An ignoble approach to large field inflation (2010, background): “The observed universe can have a small negative spatial curvature which is potentially observable in future experiments [73].”
• Inflationary paradigm after Planck 2013 (2013, background): “) Moreover, the evolution of the bubble universe after tunneling begins with φ̇ = 0 and strong Hubble damping of φ̇ (H ∼ 1/t), so at least in simple models [33,34] φ̇2 is never large enough to interfere with the onset of slow-roll inflation.”
• Sinks in the landscape, Boltzmann brains and the cosmological constant problem (2006, background): “The last part (which we will not consider in this paper) implies, in particular, that we should pay special attention to the bubbles having inflationary universes inside, since otherwise the bubbles will be empty open universes unsuitable for life [48].”
• Inflation and String Theory (2014, background): “Negative spatial curvature resulting from tunneling entirely removes overshooting in certain classes of potential, and reduces its severity in general [661,662].”
• Issues in the Philosophy of Cosmology (2006, background): “The best current data is marginally consistent with k = −1, but the value indicated most strongly by that data is k = +1, indicating finite closed space sections rather than an infinite multiverse such as that advocated by Susskind et al [86, 212].”
• The evidence for a spatially flat Universe (2020, background): “Models of this type have been discussed by many authors in the past (e.g. Gott 1982; Linde 1995; Bucher et al. 1995; Linde et al. 1999) and they have received renewed interest in the context of false vacuum decay within a string landscape (e.g. Freivogel et al. 2006; Yamauchi et al. 2011).”
• Monodromy in the CMB: Gravity Waves and String Inflation (2008, unknown): “Similar comments apply to other corners of field theory and string theory with predictive inflationary signatures such as [27, 38, 39, 40].”