Imperial College London
Alternate

Prof Joao Magueijo

Faculty of Natural Sciences, Department of Physics

Professor of Physics
 
 
 
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Contact

 

j.magueijo Website

 
 
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Location

 

Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Magueijo:2019:10.1103/PhysRevD.100.084036,
author = {Magueijo, J and Zlosnik, T},
doi = {10.1103/PhysRevD.100.084036},
journal = {Physical Review D: Particles, Fields, Gravitation and Cosmology},
pages = {1--17},
title = {Parity violating Friedmann universes},
url = {http://dx.doi.org/10.1103/PhysRevD.100.084036},
volume = {100},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - We revisit extensions of the Einstein-Cartan theory where the cosmological constant Λ is promoted to a variable, at the cost of allowing for torsion even in the absence of spinors. We remark that some standard notions about Friedmann-Robertson-Walker (FRW) universes collapse in these theories, most notably that spatial homogeneity and isotropy may now coexist with violations of parity invariance. The parity-violating solutions have nonvanishing Weyl curvature even within FRW models. The presence of parity-violating torsion opens up the space of possible such theories with relevant FRW modifications; in particular the Pontryagin term can play an important role even in the absence of spinorial matter. We present a number of parity-violating solutions with and without matter. The former are the non-self-dual vacuum solutions long suspected to exist. The latter lead to tracking and nontracking solutions with a number of observational problems, unless we invoke the Pontryagin term. An examination of the Hamiltonian structure of the theory reveals that the parity-even and the parity-violating solutions belong to two distinct branches of the theory, with different gauge symmetries (constraints) and different numbers of degrees of freedom (d.o.f.). The parity-even branch is nothing but standard relativity with a cosmological constant which has become pure gauge under conformal invariance if matter is absent, or a slave of matter (and so not an independent d.o.f.) if nonconformally invariant matter is present. In contrast, the parity-violating branch contains a genuinely new d.o.f.
AU  - Magueijo,J
AU  - Zlosnik,T
DO  - 10.1103/PhysRevD.100.084036
EP  - 17
PY  - 2019///
SN  - 1550-2368
SP  - 1
TI  - Parity violating Friedmann universes
T2  - Physical Review D: Particles, Fields, Gravitation and Cosmology
UR  - http://dx.doi.org/10.1103/PhysRevD.100.084036
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000490475100002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://journals.aps.org/prd/abstract/10.1103/PhysRevD.100.084036
UR  - http://hdl.handle.net/10044/1/74653
VL  - 100
ER  -
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