A closed string tachyon vacuum?

Yang, Haitang; Zwiebach, Barton

doi:10.1088/1126-6708/2005/09/054

Cited by 74 publications

(135 citation statements)

References 48 publications

(75 reference statements)

Supporting

Mentioning

128

Contrasting

Order By: Relevance

“…The behavior of a + σ a , a and a − σ a can be seen in the figure below, where the collapse of the universe can be seen directly, which is consistent with the nature of this tachyon potential as stated in [10]. …”

Section: Scale Factor Expectation Valuesupporting

confidence: 84%

A premier analysis of supersymmetric closed string tachyon cosmology

Vázquez-Báez

Ramı́rez

2018

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. From a previously found worldline supersymmetric formulation for the effective action of the closed string tachyon in a FRW background, the Hamiltonian of the theory is constructed, by means of the Dirac procedure, and written in a quantum version. Using the supersymmetry algebra we are able to find solutions to the Wheeler-DeWitt equation via a more simple set of first order differential equations. Finally, for the k = 0 case, we compute the expectation value of the scale factor with a suitably potential also favored in the present literature. We give some interpretations of the results and state future work lines on this matter. IntroductionTachyons correspond to the lowest mode of string theory, which for the lack of knowledge on how to handle unstable configurations were ignored for many years. With the inclusion of supersymmetry they can be consistently eliminated from the spectrum by the GSO truncation. Some years ago it has been seen that the evolution of these tachyonic instabilities can be described by the condensation of the tachyonic modes. This was first perfomed in the simpler case of open strings, resumed by the well known Sen conjectures [1]. Whereas for closed strings the situation is more complicated, because it involves the structure of space-time. A key element for the development of the present work is the interesting fact that closed string tachyons, which are nonsupersymmetric in the target space, can have worldsheet supersymmetry [2]. Supersymmetric cosmology has been studied in a variety of different schemes, we refer the interested reader to the well known books by D'Eath and Moniz for a review [3,4]. In [5] a Lagrangian of supersymmetric tachyons in the framework of a FRW background was given in a worldline superspace where, the time variable is extended to the superspace of supersymmetry [6,7], this is done considering the covariant formulation of one-dimensional supergravity of the so called 'new ' Θ variables [8, 9], which allows in a straightforward way to write supergravity invariant actions. The present work is performed along such approach, we depart from the Hamiltonian given in [5], then we give a particular, and normalizable, solution to the WheelerDeWitt equation via the superalgebra constraints, which act as square roots of the WDW equation. We compute the scale factor expectation value as customary. Plots of the results are given, follow up by some conclusions and final remarks on future work.

show abstract

Section: Scale Factor Expectation Valuesupporting

confidence: 84%

A premier analysis of supersymmetric closed string tachyon cosmology

Vázquez-Báez

Ramı́rez

2018

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…At this stage, a simple exercise is to find linearized modes ofσ and σ that are plane waves in the spatial directions:σ 56) and A is an arbitrary mode amplitude. Moving back to FRW time and the σ normalization for the scalar field, we recover the form 57) for the overdamped modes, 4 where .…”

Section: Fluctuations Of the Metric And Dilatonmentioning

confidence: 99%

Cosmological solutions of supercritical string theory

2008

View full text Add to dashboard Cite

We study quintessence-driven, spatially flat, expanding FRW cosmologies that arise naturally from string theory formulated in a supercritical number of spacetime dimensions. The treelevel potential of the string theory produces an equation of state at the threshold between accelerating and decelerating cosmologies, and the resulting spacetime is globally conformally equivalent to Minkowski space. We demonstrate that exact solutions exist with a condensate of the closed-string tachyon, the simplest of which is a Liouville wall moving at the speed of light. We rely on the existence of this solution to derive constraints on the couplings of the tachyon to the dilaton and metric in the string theory effective action. In particular, we show that the tachyon dependence of the Einstein term must be nontrivial.

show abstract

“…Finally, analogously to the case of open string tachyons (for a review, see [32]), closed string tachyons may be a subject well-studied via closed string field theory; a candidate "nothing" state obtained from bosonic closed string bulk tachyon condensation was recently presented in [33]. It is clear (as we will review as we go) that the physics of the tachyon condensate is stringy -low energy effective field theory is not sufficient.…”

Section: Introductionmentioning

confidence: 99%

The tachyon at the end of the universe

McGreevy¹,

Silverstein²

2005

J. High Energy Phys.

126

241

View full text Add to dashboard Cite

We show that a tachyon condensate phase replaces the spacelike singularity in certain cosmological and black hole spacetimes in string theory. We analyze explicitly a set of examples with flat spatial slices in various dimensions which have a winding tachyon condensate, using worldsheet path integral methods from Liouville theory. In a vacuum with no excitations above the tachyon background in the would-be singular region, we analyze the production of closed strings in the resulting state in the bulk of spacetime. We find a thermal result reminiscent of the Hartle-Hawking state, with tunably small energy density. The amplitudes exhibit a self-consistent truncation of support to the weakly-coupled small-tachyon region of spacetime. We argue that the background is accordingly robust against back reaction, and that the resulting string theory amplitudes are perturbatively finite, indicating a resolution of the singularity and a mechanism to start or end time in string theory. Finally, we discuss the generalization of these methods to examples with positively curved spatial slices.

show abstract

A closed string tachyon vacuum?

Cited by 74 publications

References 48 publications

A premier analysis of supersymmetric closed string tachyon cosmology

A premier analysis of supersymmetric closed string tachyon cosmology

Cosmological solutions of supercritical string theory

The tachyon at the end of the universe

Contact Info

Product

Resources

About