Diluting the cosmological constant in infinite volume extra dimensions

Dvali, Gia; Gabadadze, Gregory; Shifman, M.

doi:10.1103/physrevd.67.044020

Cited by 195 publications

(292 citation statements)

References 58 publications

Supporting

Mentioning

284

Contrasting

Order By: Relevance

“…In D = 6 bulk space-time dimensions, for instance, a co-dimension 2 brane, like a cosmic string, should create a deficit angle in the extra dimensions while remaining flat. For D > 6, it has been argued that a brane with tension should inflate, but with a Hubble rate that is inversely proportional to the brane tension [767].…”

Section: Degravitationmentioning

confidence: 99%

“…we are able to ask the slightly different: why does the cosmological constant not gravitate very strongly? [767][768][769] This is an interesting viewpoint; up to now we have been fighting Λ, trying to make its value small, but this allows us to take seriously the notion that the large cosmological constant generated via matter loops is physical, and that it does not strongly curve space-time. This phenomenon of degravitation is intimately tied to massive gravity: as we will see below, any theory that exhibits degravitation must reduce, to a theory of massive/resonance gravity at the linearized level [769].…”

Section: Degravitationmentioning

confidence: 99%

See 1 more Smart Citation

Beyond the cosmological standard model

et al. 2015

View full text Add to dashboard Cite

After a decade and a half of research motivated by the accelerating universe, theory and experiment have a reached a certain level of maturity. The development of theoretical models beyond Λ or smooth dark energy, often called modified gravity, has led to broader insights into a path forward, and a host of observational and experimental tests have been developed. In this review we present the current state of the field and describe a framework for anticipating developments in the next decade. We identify the guiding principles for rigorous and consistent modifications of the standard model, and discuss the prospects for empirical tests.We begin by reviewing recent attempts to consistently modify Einstein gravity in the infrared, focusing on the notion that additional degrees of freedom introduced by the modification must "screen" themselves from local tests of gravity. We categorize screening mechanisms into three broad classes: mechanisms which become active in regions of high Newtonian potential, those in which first derivatives of the field become important, and those for which second derivatives of the field are important. Examples of the first class, such as f (R) gravity, employ the familiar chameleon or symmetron mechanisms, whereas examples of the last class are galileon and massive gravity theories, employing the Vainshtein mechanism. In each case, we describe the theories as effective theories and discuss prospects for completion in a more fundamental theory. We describe experimental tests of each class of theories, summarizing laboratory and solar system tests and describing in some detail astrophysical and cosmological tests. Finally, we discuss prospects for future tests which will be sensitive to different signatures of new physics in the gravitational sector.The review is structured so that those parts that are more relevant to theorists vs. observers/experimentalists are clearly indicated, in the hope that this will serve as a useful reference for both audiences, as well as helping those interested in bridging the gap between them.

show abstract

Section: Degravitationmentioning

confidence: 99%

Section: Degravitationmentioning

confidence: 99%

Beyond the cosmological standard model

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The extension to higher dimensions is particularly important both for its possible embedding into string theory and for its relevance to the CC problem [3,4]. However, the natural generalization of the DGP model with higher codimension branes is not straightforward [5,6].…”

mentioning

confidence: 99%

“…M ÿ4 6 log p=m 6 , reproducing the codimension 2 Green's function with a physical cutoff given by m 6 . The corresponding 4D Newtonian potential scales as 1=r 3 at the largest distances, showing that the theory becomes six dimensional, and reduces to the usual 1=r on the shortest scales. Its behavior at intermediate distances, however, depends on m 5;6 .…”

mentioning

confidence: 99%

Cascading Gravity: Extending the Dvali-Gabadadze-Porrati Model to Higher Dimension

et al. 2008

Self Cite

View full text Add to dashboard Cite

We present a generalization of the Dvali-Gabadadze-Porrati scenario to higher codimensions which, unlike previous attempts, is free of ghost instabilities. The 4D propagator is made regular by embedding our visible 3-brane within a 4-brane, each with their own induced gravity terms, in a flat 6D bulk. The model is ghost-free if the tension on the 3-brane is larger than a certain critical value, while the induced metric remains flat. The gravitational force law ''cascades'' from a 6D behavior at the largest distances followed by a 5D and finally a 4D regime at the shortest scales. Introduction.-The present acceleration of the Universe is a profound mystery. While the observational data are consistent with a cosmological constant (CC) of order 10 ÿ3 eV 4 , this value is in stark disagreement with particle physics computations. The problem is even more severe than the hierarchy problem in the Standard Model, since dynamical solutions are impossible in theories with a massless 4D graviton [1]. In the same way as the perihelion precession of Mercury was explained by a modification of Newtonian gravity, an alternative approach is to assume that the acceleration signals a breakdown of general relativity at cosmological distances.The Dvali-Gabadadze-Porrati (DGP) model [2] provides a simple mechanism to modify gravity at large distances by adding a localized graviton kinetic term on a codimension 1 brane in a flat 5D spacetime. The extension to higher dimensions is particularly important both for its possible embedding into string theory and for its relevance to the CC problem [3,4]. However, the natural generalization of the DGP model with higher codimension branes is not straightforward [5,6]. On the one hand, these models require some regularization due to the divergent behavior of the Green's functions in higher codimension. More seriously, most constructions are plagued by ghost instabilities around flat space (not to be confused with those of the selfaccelerating branch of standard 5D DGP) [5,6]-see [7] for related work. The purpose of this Letter is to show that both pathologies can be resolved by embedding the codimension 2 DGP model into a codimension 1 brane with its own kinetic term. It will be interesting to see if this setup allows for higher-codimension self-accelerated solutions. Our present focus, however, is to derive a consistent framework in which gravity is modified in the infrared.Scalar.-We shall focus on the codimension 2 case. As a warm-up, we consider a real scalar field with action,

show abstract

“…In order for the mechanism to work it is required that the supersymmetry breaking on the brane does not propagate to the bulk. This is the weak point of the scheme for a finite volume 2-manifold, as has been argued in a very general context in [13]. We hope that some other variations of the idea will make a dent on this very important unsolved problem.…”

Section: Introductionmentioning

confidence: 99%

Scalar potential and dyonic strings in 6D gauged supergravity

RANDJBARDAEMI

2004

Nuclear Physics B

View full text Add to dashboard Cite

In this paper we first give a simple parametrization of the scalar coset manifold of the only known anomaly free chiral gauged supergravity in six dimensions in the absence of linear multiplets, namely gauged minimal supergravity coupled to a tensor multiplet, E 6 × E 7 × U (1) R Yang-Mills multiplets and suitable number of hypermultiplets. We then construct the potential for the scalars and show that it has a unique minimum at the origin. We also construct a new BPS dyonic string solution in which U (1) R × U (1) gauge fields, in addition to the metric, dilaton and the 2-form potential, assume nontrivial configurations in any U (1) R gauged 6D minimal supergravity coupled to a tensor multiplet with gauge symmetry G ⊇ U (1). The solution preserves 1/4 of the 6D supersymmetries and can be trivially embedded in the anomaly free model, in which case the U (1) activated in our solution resides in E 7 .

show abstract

Diluting the cosmological constant in infinite volume extra dimensions

Cited by 195 publications

References 58 publications

Beyond the cosmological standard model

Beyond the cosmological standard model

Cascading Gravity: Extending the Dvali-Gabadadze-Porrati Model to Higher Dimension

Scalar potential and dyonic strings in 6D gauged supergravity

Contact Info

Product

Resources

About