scholarly journals Crisis on infinite earths: short-lived de Sitter vacua in the string theory landscape

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Heliudson Bernardo ◽  
Suddhasattwa Brahma ◽  
Keshav Dasgupta ◽  
Radu Tatar

Abstract We construct purely non-perturbative anti-de Sitter vacua in string theory which, on uplifting to a de Sitter (dS) one, have a decay time many orders of magnitude smaller than those of standard constructions, such as the KKLT and LVS scenarios. By virtue of being constructed purely from non-perturbative terms, these vacua avoids certain obstructions plaguing other constructions of dS in string theory. This results in a new class of phenomenological dS vacua in string theory with novel distinctive characteristics such as having two maxima. After examining whether these uplifted dS vacua obey the TCC, we revisit some old problems of realization of dS space as a vacuum. We find that not only is it phenomenologically hard to construct TCC-compatible vacua, but also inherent temporal dependences of the degrees of freedom generically arise in such constructions, amongst other issues. This reinforces the idea that dS, if it exists in string theory, should be a Glauber-Sudarshan state and not a vacuum.

2016 ◽  
Vol 94 (8) ◽  
Author(s):  
Ana Achúcarro ◽  
Pablo Ortiz ◽  
Kepa Sousa

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Sukruti Bansal ◽  
Silvia Nagy ◽  
Antonio Padilla ◽  
Ivonne Zavala

Abstract Recent progress in understanding de Sitter spacetime in supergravity and string theory has led to the development of a four dimensional supergravity with spontaneously broken supersymmetry allowing for de Sitter vacua, also called de Sitter supergravity. One approach makes use of constrained (nilpotent) superfields, while an alternative one couples supergravity to a locally supersymmetric generalization of the Volkov-Akulov goldstino action. These two approaches have been shown to give rise to the same 4D action. A novel approach to de Sitter vacua in supergravity involves the generalisation of unimodular gravity to supergravity using a super-Stückelberg mechanism. In this paper, we make a connection between this new approach and the previous two which are in the context of nilpotent superfields and the goldstino brane. We show that upon appropriate field redefinitions, the 4D actions match up to the cubic order in the fields. This points at the possible existence of a more general framework to obtain de Sitter spacetimes from high-energy theories.


2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Ignatios Antoniadis ◽  
Yifan Chen ◽  
George K. Leontaris

2012 ◽  
Vol 21 (11) ◽  
pp. 1241004 ◽  
Author(s):  
TOM BANKS

The theory of holographic spacetime (HST) generalizes both string theory and quantum field theory (QFT). It provides a geometric rationale for supersymmetry (SUSY) and a formalism in which super-Poincare invariance follows from Poincare invariance. HST unifies particles and black holes, realizing both as excitations of noncommutative geometrical variables on a holographic screen. Compact extra dimensions are interpreted as finite-dimensional unitary representations of super-algebras, and have no moduli. Full field theoretic Fock spaces, and continuous moduli are both emergent phenomena of super-Poincare invariant limits in which the number of holographic degrees of freedom goes to infinity. Finite radius de Sitter (dS) spaces have no moduli, and break SUSY with a gravitino mass scaling like Λ1/4. In regimes where the Covariant Entropy Bound is saturated, QFT is not a good description in HST, and inflation is such a regime. Following ideas of Jacobson, the gravitational and inflaton fields are emergent classical variables, describing the geometry of an underlying HST model, rather than "fields associated with a microscopic string theory". The phrase in quotes is meaningless in the HST formalism, except in asymptotically flat and AdS spacetimes, and some relatives of these.


2014 ◽  
Vol 886 ◽  
pp. 43-62 ◽  
Author(s):  
Ignatios Antoniadis ◽  
Rob Knoops

2017 ◽  
Vol 2017 (10) ◽  
Author(s):  
Diego Gallego ◽  
M. C. David Marsh ◽  
Bert Vercnocke ◽  
Timm Wrase

2011 ◽  
Vol 2011 (5) ◽  
Author(s):  
David Andriot ◽  
Enrico Goi ◽  
Ruben Minasian ◽  
Michela Petrini

2019 ◽  
Vol 28 (14) ◽  
pp. 1943002 ◽  
Author(s):  
Olaf Hohm ◽  
Barton Zwiebach

The higher-derivative [Formula: see text] corrections consistent with [Formula: see text] duality invariance can be completely classified for cosmological, purely time-dependent backgrounds. This result is used to show that there are duality invariant theories featuring string-frame de Sitter vacua as solutions that are nonperturbative in [Formula: see text], thus suggesting that classical string theory may realize de Sitter solutions in an unexpected fashion.


1990 ◽  
Vol 05 (05) ◽  
pp. 325-335 ◽  
Author(s):  
A.T. FILIPPOV ◽  
A.P. ISAEV

A new class of constrained hamiltonian systems with a finite number of bosonic and fermionic degrees of freedom is proposed. Coordinates of these systems are divided into two groups of independent variables analogous to the left and right movers of the standard closed fermionic string theory. Hamiltonians are obtained by gauging some subgroups of the linear supercanonical transformations for the left and right variables. It is argued that some of the new models can be regarded as discrete analogs of the standard fermionic string theory. The extension of the models obtained by adding ghost variables is also constructed as a prerequisite to quantizing them.


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