Ellipticity weakens chameleon screening

The chameleon mechanism enables a long-range fifth force to be screened in dense environments when nontrivial self-interactions of the field cause its mass to increase with the local density. To date, chameleon fifth forces have mainly been studied for spherically symmetric sources; however, the non...

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Main Authors: Burrage, Clare, Copeland, Edmund J., Stevenson, James
Format: Article
Published: American Physical Society 2015
Online Access:https://eprints.nottingham.ac.uk/42096/
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author Burrage, Clare
Copeland, Edmund J.
Stevenson, James
author_facet Burrage, Clare
Copeland, Edmund J.
Stevenson, James
author_sort Burrage, Clare
building Nottingham Research Data Repository
collection Online Access
description The chameleon mechanism enables a long-range fifth force to be screened in dense environments when nontrivial self-interactions of the field cause its mass to increase with the local density. To date, chameleon fifth forces have mainly been studied for spherically symmetric sources; however, the nonlinear self-interactions mean that the chameleon responds to changes in the shape of the source differently to gravity. In this work we focus on ellipsoidal departures from spherical symmetry and compute the full form of the chameleon force, comparing its shape dependence to that of gravity. Enhancement of the chameleon force by up to 40% is possible when deforming a sphere to an ellipsoid of the same mass, with an ellipticity ∼0.99.
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spelling nottingham-420962020-05-04T17:04:05Z https://eprints.nottingham.ac.uk/42096/ Ellipticity weakens chameleon screening Burrage, Clare Copeland, Edmund J. Stevenson, James The chameleon mechanism enables a long-range fifth force to be screened in dense environments when nontrivial self-interactions of the field cause its mass to increase with the local density. To date, chameleon fifth forces have mainly been studied for spherically symmetric sources; however, the nonlinear self-interactions mean that the chameleon responds to changes in the shape of the source differently to gravity. In this work we focus on ellipsoidal departures from spherical symmetry and compute the full form of the chameleon force, comparing its shape dependence to that of gravity. Enhancement of the chameleon force by up to 40% is possible when deforming a sphere to an ellipsoid of the same mass, with an ellipticity ∼0.99. American Physical Society 2015-03-25 Article PeerReviewed Burrage, Clare, Copeland, Edmund J. and Stevenson, James (2015) Ellipticity weakens chameleon screening. Physical Review D, D91 (6). 065030/1-065030/16. ISSN 2470-0029 https://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.065030 doi:10.1103/PhysRevD.91.065030 doi:10.1103/PhysRevD.91.065030
spellingShingle Burrage, Clare
Copeland, Edmund J.
Stevenson, James
Ellipticity weakens chameleon screening
title Ellipticity weakens chameleon screening
title_full Ellipticity weakens chameleon screening
title_fullStr Ellipticity weakens chameleon screening
title_full_unstemmed Ellipticity weakens chameleon screening
title_short Ellipticity weakens chameleon screening
title_sort ellipticity weakens chameleon screening
url https://eprints.nottingham.ac.uk/42096/
https://eprints.nottingham.ac.uk/42096/
https://eprints.nottingham.ac.uk/42096/