Cargando…

The Dilaton Improves Goldstones

The free scalar field is only conformally invariant when non-minimally coupled to gravity. In flat space this amounts to amending, or improving, the energy momentum tensor. A no-go theorem prohibits the improvement for Goldstone bosons, originating from global internal spontaneous symmetry breaking....

Descripción completa

Detalles Bibliográficos
Autor principal: Zwicky, Roman
Lenguaje:eng
Publicado: 2023
Materias:
Acceso en línea:http://cds.cern.ch/record/2862849
_version_ 1780977889117732864
author Zwicky, Roman
author_facet Zwicky, Roman
author_sort Zwicky, Roman
collection CERN
description The free scalar field is only conformally invariant when non-minimally coupled to gravity. In flat space this amounts to amending, or improving, the energy momentum tensor. A no-go theorem prohibits the improvement for Goldstone bosons, originating from global internal spontaneous symmetry breaking. It is shown that the no-go theorem can be circumvented in the presence of a dilaton. The latter is a (pseudo) Goldstone boson originating from spontaneous conformal symmetry breaking in a theory with an infrared fixed point. Specifically, the tracelessness of the energy momentum tensor is demonstrated for a generic $d$-dimensional curved space. Additionally, the Goldstone gravitational form factors are shown to obey conformality constraints in the soft limit. The crucial point is that the remainder term of the soft theorem is non-zero due to the presence of the dilaton pole. For Goldstone systems with a trivial infrared fixed point the leading order analysis of this paper ought to be sufficient. Loop effects govern the improvement term outside the fixed point and are scheme-dependent as briefly discussed towards the end of the paper.
id cern-2862849
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2023
record_format invenio
spelling cern-28628492023-10-05T04:27:39Zhttp://cds.cern.ch/record/2862849engZwicky, RomanThe Dilaton Improves Goldstoneshep-phParticle Physics - Phenomenologyhep-latParticle Physics - Latticegr-qcGeneral Relativity and Cosmologyhep-thParticle Physics - TheoryThe free scalar field is only conformally invariant when non-minimally coupled to gravity. In flat space this amounts to amending, or improving, the energy momentum tensor. A no-go theorem prohibits the improvement for Goldstone bosons, originating from global internal spontaneous symmetry breaking. It is shown that the no-go theorem can be circumvented in the presence of a dilaton. The latter is a (pseudo) Goldstone boson originating from spontaneous conformal symmetry breaking in a theory with an infrared fixed point. Specifically, the tracelessness of the energy momentum tensor is demonstrated for a generic $d$-dimensional curved space. Additionally, the Goldstone gravitational form factors are shown to obey conformality constraints in the soft limit. The crucial point is that the remainder term of the soft theorem is non-zero due to the presence of the dilaton pole. For Goldstone systems with a trivial infrared fixed point the leading order analysis of this paper ought to be sufficient. Loop effects govern the improvement term outside the fixed point and are scheme-dependent as briefly discussed towards the end of the paper.arXiv:2306.12914CERN-TH-2023-101oai:cds.cern.ch:28628492023-06-22
spellingShingle hep-ph
Particle Physics - Phenomenology
hep-lat
Particle Physics - Lattice
gr-qc
General Relativity and Cosmology
hep-th
Particle Physics - Theory
Zwicky, Roman
The Dilaton Improves Goldstones
title The Dilaton Improves Goldstones
title_full The Dilaton Improves Goldstones
title_fullStr The Dilaton Improves Goldstones
title_full_unstemmed The Dilaton Improves Goldstones
title_short The Dilaton Improves Goldstones
title_sort dilaton improves goldstones
topic hep-ph
Particle Physics - Phenomenology
hep-lat
Particle Physics - Lattice
gr-qc
General Relativity and Cosmology
hep-th
Particle Physics - Theory
url http://cds.cern.ch/record/2862849
work_keys_str_mv AT zwickyroman thedilatonimprovesgoldstones
AT zwickyroman dilatonimprovesgoldstones