Kasner solutions, climbing scalars and big-bang singularity

Condeescu, Cezar; Dudas, Emilian

doi:10.1088/1475-7516/2013/08/013

Cited by 19 publications

(24 citation statements)

References 94 publications

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“…A minimal well motivated choice is [65] which generalizes the choice in [21,57]. "Critical" potential wells are special, and the reader is referred to [67] for some amusing details.…”

Section: Sgoldstino-less Models Vs String Theory: Climbing Scalarsmentioning

confidence: 99%

Supersymmetry and Inflation

Ferrara¹,

Sagnotti²

2016

Proceedings of 18th International Conference From the Planck Scale to the Electroweak Scale — PoS(PLANCK 2015)

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Theories with elementary scalar degrees of freedom seem nowadays required for simple descriptions of the Standard Model and of the Early Universe. It is then natural to embed theories of inflation in supergravity, also in view of their possible ultraviolet completion in String Theory. After some general remarks on inflation in supergravity, we describe examples of minimal inflaton dynamics which are compatible with recent observations, including higher-curvature ones inspired by the Starobinsky model. We also discuss different scenarios for supersymmetry breaking during and after inflation, which include a revived role for nonlinear realizations. In this spirit, we conclude with a discussion of the link, in four dimensions, between "brane supersymmetry breaking" and the super-Higgs effect in supergravity.

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“…A minimal well motivated choice is [65] which generalizes the choice in [21,57]. "Critical" potential wells are special, and the reader is referred to [67] for some amusing details.…”

Section: Sgoldstino-less Models Vs String Theory: Climbing Scalarsmentioning

confidence: 99%

Supersymmetry and Inflation

Ferrara¹,

Sagnotti²

2016

Proceedings of 18th International Conference From the Planck Scale to the Electroweak Scale — PoS(PLANCK 2015)

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“…• once the scalar is forbidden to emerge while descending the potential, the string coupling is bounded from above, rendering this behavior naturally protected against string loops (although not against α ′ string corrections [18]);…”

Section: Climbing Scalars In Briefmentioning

confidence: 99%

“…Mild exponential potentials supporting inflation were indeed studied since the 1980's [15,16], but remarkably the exponent in eq. (2.8) sits precisely at a (steep) critical value where it starts to become impossible, for φ, to emerge from an initial singularity while descending the potential [17] (at least in the two-derivative approximation [18]). Hence, the climbing scalar generically reaches up to a point where it reverts its motion and starts to descend.…”

Section: Introductionmentioning

confidence: 96%

Low-ℓ CMB from string-scale SUSY breaking?

Sagnotti

2016

Mod. Phys. Lett. A

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Models of inflation are instructive playgrounds for supersymmetry breaking in Supergravity and String Theory. In particular, combinations of branes and orientifolds that are not mutually BPS can lead to brane supersymmetry breaking, a phenomenon where non-linear realizations are accompanied, in tachyon-free vacua, by the emergence of steep exponential potentials. When combined with milder terms, these exponentials can lead to slow-roll after a fast ascent and a turning point. This leaves behind distinctive patterns of scalar perturbations, where pre-inflationary peaks can lie well apart from an almost scale invariant profile. I review recent attempts to connect these power spectra to the low-ℓ CMB, and a corresponding one-parameter extension of ΛCDM with a low-frequency cut ∆. A detailed likelihood analysis led to ∆ = (0.351 ± 0.114) × 10 −3 Mpc −1 , at 99.4% confidence level, in an extended Galactic mask with f sky = 39%, to be compared with a nearby value at 88.5% in the standard Planck 2015 mask with f sky = 94%. In these scenarios one would be confronted, in the CMB, with relics of an epoch of deceleration that preceded the onset of slow-roll.

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“…The power suppression on large angular scales has also been implemented in fiber inflation [19][20][21], and also [15,16] for brane SUSY breaking models [53][54][55], and [56,57] for the punctuated inflation. However, how to explain the dipole power asymmetry in the CMB was not illustrated in these studies.…”

Section: The Modulating Mode From a Superinflationary Phasementioning

confidence: 99%

“…In this angle of view, the anomalies on large angular scales may be a hint of the pre-inflationary physics, which might be relevant with the initial singularity, e.g. [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

CMB anomalies from an inflationary model in string theory

Liu¹,

Guo²,

Piao³

2014

Eur. Phys. J. C

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Recent Planck measurements show some CMB anomalies on large angular scales, which confirms the early observations by WMAP. We show that an inflationary model, in which before the slow-roll inflation the Universe is in a superinflationary phase, can generate a large-scale cutoff in the primordial power spectrum, which may account for not only the power suppression on large angular scales, but also a large dipole power asymmetry in the CMB. We discuss an implementation of our model in string theory.

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Kasner solutions, climbing scalars and big-bang singularity

Cited by 19 publications

References 94 publications

Supersymmetry and Inflation

Supersymmetry and Inflation

Low-ℓ CMB from string-scale SUSY breaking?

CMB anomalies from an inflationary model in string theory

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