Phenomenological gravitational constraints on strings and higher-dimensional theories

Kostelecký, V. Alan; Samuel, Stuart

doi:10.1103/physrevlett.63.224

Cited by 401 publications

(334 citation statements)

References 15 publications

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“…For instance, the possibility of spontaneous Lorentz and CPT breaking in the framework of string field theory was discovered more than a decade ago [67][68][69][70][71][72][73][74]. Subsequent studies have considered other mechanisms for Lorentzviolating vacua including spacetime foam [75,76], nontrivial spacetime topology [77], loop quantum gravity [78,79], realistic noncommutative field theories [80][81][82][83], and spacetime-varying couplings [1,84].…”

Section: Coordinate Independencementioning

confidence: 99%

The Lorentz-Violating Extension of the Standard Model

Lehnert

2004

Beyond the Desert 2003

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Abstract. Quantum-gravity effects are expected to be suppressed by the Planck mass. For experimental progress it is therefore important to identify potential signatures from Planck-scale physics that are amenable to ultrahigh-precision tests. It is argued that minuscule violations of Lorentz and CPT symmetry are candidate signals. In addition, theoretical and experimental aspects of the Standard-Model Extension, which describes the emergent low-energy effects, are discussed. MotivationAn important open question in our understanding of nature at its fundamental level concerns a unified quantum description of all fundamental interactions including gravity. Such a theory is likely to become dominant only as the Planck scale is approached, so that quantum-gravity effects are expected to be minuscule at presently attainable energies. Moreover, the absence of a fully realistic and viable candidate underlying theory provides a major obstacle for the identification of concrete quantum-gravity signatures that can be searched for in present-day or near-future experiments.A possible approach to overcome this phenomenological issue is to determine exact relations in the currently accepted laws of physics that may be violated in prospective fundamental theories and that can be tested with ultrahighprecision. Symmetries typically satisfy these criteria. For example, Lorentz and CPT invariance are cornerstones of our present understanding of nature at the fundamental level, and a variety of Lorentz and CPT tests belong to the most sensitive null experiments available. Lorentz and CPT violation is also a key feature of certain approaches to underlying physics.For example, couplings varying on cosmological scales are one possible source of Lorentz and CPT violation [1]. This fact does not come as a surprise: parameters dependent on spacetime break translational invariance, and translations, rotations, and boosts are linked in the Poincaré group. Thus, violations of translation symmetry can also affect Lorentz invariance. This can be understood intuitively as follows. The equations of motion typically contain the gradient of the coupling, which selects a preferred direction in spacetime leading to apparent Lorentz violation.In this talk, we discuss some theoretical and experimental aspects of the Standard-Model Extension (SME) [2][3][4][5][6][7], which is the low-energy framework for Lorentz-breaking effects. The SME is a dynamical model constructed to contain all Lorentz-and CPT-violating lagrangian terms consistent with coordinate

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Section: Coordinate Independencementioning

confidence: 99%

The Lorentz-Violating Extension of the Standard Model

Lehnert

2004

Beyond the Desert 2003

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“…The SME is an extension of the usual standard model including new terms or couplings between the LV backgrounds and the standard model fields. The LV backgrounds arise as vacuum expectation values of tensor fields due to a spontaneous Lorentz-symmetry breaking occurring in a theory at very high energy scale [10,11]. The study of the Lorentz-violating effects on the formation of topological defects was firstly considered in the solitonic solutions generated by scalar fields in Refs.…”

Section: Introductionmentioning

confidence: 99%

Topological self-dual configurations in a Maxwell–Higgs model with a CPT-odd and Lorentz-violating nonminimal coupling

2016

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We have studied the existence of topological self-dual configurations in a nonminimal CPT-odd and Lorentzviolating (LV) Maxwell-Higgs model, where the LV interaction is introduced by modifying the minimal covariant derivative. The Bogomol'nyi-Prasad-Sommerfield formalism has been implemented, revealing that the scalar self-interaction implying self-dual equations contains a derivative coupling. The CPT-odd self-dual equations describe electrically neutral configurations with finite total energy proportional to the total magnetic flux, which differ from the charged solutions of other CPT-odd and LV models previously studied. In particular, we have investigated the axially symmetrical self-dual vortex solutions altered by the LV parameter. For large distances, the profiles possess general behavior similar to the vortices of Abrikosov-Nielsen-Olesen. However, within the vortex core, the profiles of the magnetic field and energy can differ substantially from ones of the Maxwell-Higgs model depending if the LV parameter is negative or positive.

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“…This possibility arises explicitly from solutions of string field theory, at least for the open type I bosonic string, as interactions are cubic in the string field and these give origin in the static field theory potential to cubic interaction terms of the type SSS, ST T and T T T , where S and T denote scalar and tensor fields. The way Lorentz invariance may be broken can be seen, for instance, from the static potential involving the tachyon and a generic vector field as can be explicitly computed [13]:…”

Section: Introductionmentioning

confidence: 99%

“…In the context of string theories, conformal invariance may be broken actually due to the possibility of spontaneous breaking of the Lorentz invariance [13] (this breaking can also lead to the breaking of CPT symmetry [14]). This possibility arises explicitly from solutions of string field theory, at least for the open type I bosonic string, as interactions are cubic in the string field and these give origin in the static field theory potential to cubic interaction terms of the type SSS, ST T and T T T , where S and T denote scalar and tensor fields.…”

Section: Introductionmentioning

confidence: 99%

Primordial magnetic fields via spontaneous breaking of Lorentz invariance

Bertolami¹,

Mota²

1999

Physics Letters B

132

113

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Spontaneous breaking of Lorentz invariance compatible with observational limits may realistically take place in the context of string theories, possibly endowing the photon with a mass.In this process the conformal symmetry of the electromagnetic action is broken allowing for the possibility of generating large scale (∼ Mpc) magnetic fields within inflationary scenarios. We show that for reheating temperatures safe from the point of view of the gravitino and moduli problem, T RH < ∼ 10 9 GeV for m 3/2 ≈ 1 T eV , the strength of the generated seed fields is, in our mechanism, consistent with amplification by the galactic dynamo processes and can be even as large as to explain the observed galactic magnetic fields through the collapse of protogalactic clouds. PACS number(s): 98.80 Cq, 98.62 En

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Phenomenological gravitational constraints on strings and higher-dimensional theories

Cited by 401 publications

References 15 publications

The Lorentz-Violating Extension of the Standard Model

The Lorentz-Violating Extension of the Standard Model

Topological self-dual configurations in a Maxwell–Higgs model with a CPT-odd and Lorentz-violating nonminimal coupling

Primordial magnetic fields via spontaneous breaking of Lorentz invariance

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