On the possibility of tree-level leptogenesis from Kalb–Ramond torsion background

Cesare, Marco de; Mavromatos, Nick E.; Sarkar, Sarben

doi:10.1140/epjc/s10052-015-3731-z

Cited by 53 publications

(305 citation statements)

References 81 publications

(181 reference statements)

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“…As we argued in [21], it is conceivable that in the presence of high temperature and densities of fermions (relevant for the early universe), one may have (Lorentz-violating) perturbative vacua of string theory corresponding to a constant H-torsion. In the presence of such ground states, the maintenance of rotational symmetries implies that only the temporal components of currents are allowed to condense.…”

Section: Lorentz and Cpt Violating Geometries (With Torsion) In The Strmentioning

confidence: 93%

“…The structure of the talk is the following: in section 2 we discuss geometries of the early universe which can provide the required CPT and Lorentz violating backgrounds. The latter are associated with a constant (in the cosmological Robertson-Walker frame) torsion in the context of a string-inspired theoretical model [20,21], which will constitute the focus of our discussion. In section 3 we analyse the dynamics of a right-handed neutrino (RHN) in the presence of such axial backgrounds [21].…”

Section: Theoretical Motivations For Lorentz and Cpt Violationmentioning

confidence: 99%

“…The latter are associated with a constant (in the cosmological Robertson-Walker frame) torsion in the context of a string-inspired theoretical model [20,21], which will constitute the focus of our discussion. In section 3 we analyse the dynamics of a right-handed neutrino (RHN) in the presence of such axial backgrounds [21]. The coupling of the RHN to the torsion has non trivial CP violating effects in its decay to Higgs and active neutrinos, leading to a lepton asymmetry, which is estimated.…”

Section: Theoretical Motivations For Lorentz and Cpt Violationmentioning

confidence: 99%

“…In the presence of such ground states, the maintenance of rotational symmetries implies that only the temporal components of currents are allowed to condense. From (6), then, upon replacing J 05 by the condensate ⟨J 05 ⟩, it becomes clear that the fermion condensate can be a source of torsion [21]:…”

Section: Lorentz and Cpt Violating Geometries (With Torsion) In The Strmentioning

confidence: 99%

“…(2)) a constant H-torsion in the frame of a Robertson-Walker observer. It is important to notice [21] that the index i does not include to Majorana fermions (e.g. neutrinos), as for such species the condensate vanishes.…”

Section: Lorentz and Cpt Violating Geometries (With Torsion) In The Strmentioning

confidence: 99%

See 4 more Smart Citations

Proceedings of the 12th International Conference on Low Energy Antiproton Physics (LEAP2016)

Hiyama¹,

Kanai²,

Ulmer

et al. 2017

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I review briefly string-inspired models of the Early Universe in which the Robertson-Walker geometry is extended to involve appropriate torsion fields that are constant in the frame of a cosmological observer. Fermion fields in such geometries are described by Lagrangians that fall in the simplest Lorentz-and CPT-violating extensions of the Standard Model (SME), in which the fermions couple to a constant axial vector background b µ γ 5 , with the b µ "axion-like" field associated to torsion. In the talk I also review mechanisms to suppress the torsion in the current era, compatible with the existing stringent upper bounds, which are of relevance to searches for CPT violation of interest to this conference. KEYWORDS:Early Universe, Torsion, Strings, Standard Model Extension, CPT Violation Theoretical motivations for Lorentz and CPT ViolationBaryogenesis/Leptogenesis, that is processes in the early Universe that lead to the observed matter-antimatter asymmetry in the Cosmos, represent a long-standing unresolved issue in cosmology [1]. Many approaches to the problem proposed in the literature [2] but no consensus has emerged on the potential mechanisms. Many of them predict lepton number violation, and in particular some of them entail [3] a µ → e − γ interaction with predictions on the corresponding branching ratio which may be falsified at the next generation experiments, but others are more difficult to falsify.A standard measure of the abundance of baryons over that of antibaryons is defined by the ratiowhere n B is the number density of baryons, nB is the number density of antibaryons and n γ is the density of photons (proportional to the entropy density s). This number was determined with accurate measurements of the CMB radiation by the experiments WMAP [5] and Planck [6]. However, there is no experimental evidence for primordial antimatter in the visible universe. Similarly, the generation of an asymmetry between leptons and antileptons is known as leptogenesis. This is expected to be of the same order of magnitude as Y ∆B . If B, the net baryon number, is conserved in Nature, the matter asymmetry can only originate from an asymmetric initial condition B 0. However, such an asymmetry would rapidly diminish during inflation, and extreme fine tuning of the initial condition would become necessary. This is highly unsatisfactory from a theoretical point of view. Consequently a mechanism for the dynamical generation of a baryon asymmetry is required. In the seminal paper [7], Sakharov identified three sufficient conditions that must be satisfied in order to produce a net baryon number.(1) The theory must allow for interactions that violate B conservation. These interactions must become effective at high energy scales in order to guarantee the stability of the proton. (2) Both discrete symmetries C (charge conjugation) and CP (where P denotes parity) are violated.In fact C violation is not enough, as correlations between the spins of particles and antiparticles 1

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Section: Lorentz and Cpt Violating Geometries (With Torsion) In The Strmentioning

confidence: 93%

Section: Theoretical Motivations For Lorentz and Cpt Violationmentioning

confidence: 99%

Section: Theoretical Motivations For Lorentz and Cpt Violationmentioning

confidence: 99%

Section: Lorentz and Cpt Violating Geometries (With Torsion) In The Strmentioning

confidence: 99%

Section: Lorentz and Cpt Violating Geometries (With Torsion) In The Strmentioning

confidence: 99%

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Proceedings of the 12th International Conference on Low Energy Antiproton Physics (LEAP2016)

Hiyama¹,

Kanai²,

Ulmer

et al. 2017

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Cosmological implications of Kalb-Ramond-like particles

Capanelli,

Jenks,

Kolb

et al. 2024

J. High Energ. Phys.

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The Kalb-Ramond field is an antisymmetric, rank-two tensor field which most notably appears in the context of string theory, but has largely been unexplored in the context of cosmology. In this work, motivated by the Kalb-Ramond field in string theory, and antisymmetric tensor fields that emerge in effective field theories ranging from particle physics to condensed matter, we study the primordial production of interacting massive Kalb-Ramond-like-particles (KRLPs). KRLPs contain features of both dark photon and axion models, which can be appreciated via their duality properties. While the massless non-interacting KRLP is dual to a pseudoscalar, and the massive non-interacting KRLP is dual to a pseudovector, the interacting massive KRLP can be distinguished from its scalar and vector counterparts. We study early-universe production of KRLPs via the freeze-in mechanism, considering a ‘dark photon-like’ interaction, an ‘axion-like’ interaction, and a ‘Higgs portal’ interaction, as well as production via cosmological gravitational particle production. We find that as a dark matter candidate, KRLPs can be produced by all of the above mechanisms and account for the relic density of dark matter today for a wide range of masses. Finally, we comment on the potential to obtain both warm and cold dark matter subcomponents, and speculate on observational and experimental prospects.

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Fermionic greybody factors and quasinormal modes of black holes in Kalb–Ramond gravity

Al-Badawi,

Kraishan

2023

Annals of Physics

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On the possibility of tree-level leptogenesis from Kalb–Ramond torsion background

Cited by 53 publications

References 81 publications

Proceedings of the 12th International Conference on Low Energy Antiproton Physics (LEAP2016)

Proceedings of the 12th International Conference on Low Energy Antiproton Physics (LEAP2016)

Cosmological implications of Kalb-Ramond-like particles

Fermionic greybody factors and quasinormal modes of black holes in Kalb–Ramond gravity

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