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Burrage C, Sakstein J. Tests of chameleon gravity. LIVING REVIEWS IN RELATIVITY 2018; 21:1. [PMID: 29576739 PMCID: PMC5856913 DOI: 10.1007/s41114-018-0011-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
Theories of modified gravity, where light scalars with non-trivial self-interactions and non-minimal couplings to matter-chameleon and symmetron theories-dynamically suppress deviations from general relativity in the solar system. On other scales, the environmental nature of the screening means that such scalars may be relevant. The highly-nonlinear nature of screening mechanisms means that they evade classical fifth-force searches, and there has been an intense effort towards designing new and novel tests to probe them, both in the laboratory and using astrophysical objects, and by reinterpreting existing datasets. The results of these searches are often presented using different parametrizations, which can make it difficult to compare constraints coming from different probes. The purpose of this review is to summarize the present state-of-the-art searches for screened scalars coupled to matter, and to translate the current bounds into a single parametrization to survey the state of the models. Presently, commonly studied chameleon models are well-constrained but less commonly studied models have large regions of parameter space that are still viable. Symmetron models are constrained well by astrophysical and laboratory tests, but there is a desert separating the two scales where the model is unconstrained. The coupling of chameleons to photons is tightly constrained but the symmetron coupling has yet to be explored. We also summarize the current bounds on f(R) models that exhibit the chameleon mechanism (Hu and Sawicki models). The simplest of these are well constrained by astrophysical probes, but there are currently few reported bounds for theories with higher powers of R. The review ends by discussing the future prospects for constraining screened modified gravity models further using upcoming and planned experiments.
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Affiliation(s)
- Clare Burrage
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD UK
| | - Jeremy Sakstein
- Department of Physics and Astronomy, Center for Particle Cosmology, University of Pennsylvania, Philadelphia, PA 19104 USA
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Li K, Arif M, Cory DG, Haun R, Heacock B, Huber MG, Nsofini J, Pushin DA, Saggu P, Sarenac D, Shahi CB, Skavysh V, Snow WM, Young AR. Neutron limit on the strongly-coupled chameleon field. PHYSICAL REVIEW. D. (2016) 2016; 93:10.1103/physrevd.93.062001. [PMID: 34859165 PMCID: PMC8634167 DOI: 10.1103/physrevd.93.062001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The physical origin of the dark energy that causes the accelerated expansion rate of the Universe is one of the major open questions of cosmology. One set of theories postulates the existence of a self-interacting scalar field for dark energy coupling to matter. In the chameleon dark energy theory, this coupling induces a screening mechanism such that the field amplitude is nonzero in empty space but is greatly suppressed in regions of terrestrial matter density. However measurements performed under appropriate vacuum conditions can enable the chameleon field to appear in the apparatus, where it can be subjected to laboratory experiments. Here we report the most stringent upper bound on the free neutron-chameleon coupling in the strongly coupled limit of the chameleon theory using neutron interferometric techniques. Our experiment sought the chameleon field through the relative phase shift it would induce along one of the neutron paths inside a perfect crystal neutron interferometer. The amplitude of the chameleon field was actively modulated by varying the millibar pressures inside a dual-chamber aluminum cell. We report a 95% confidence level upper bound on the neutron-chameleon coupling β ranging from β < 4.7 × 106 for a Ratra-Peebles index of n = 1 in the nonlinear scalar field potential to β < 2.4 × 107 for n = 6, one order of magnitude more sensitive than the most recent free neutron limit for intermediate n. Similar experiments can explore the full parameter range for chameleon dark energy in the foreseeable future.
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Affiliation(s)
- K. Li
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - M. Arif
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - D. G. Cory
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada
| | - R. Haun
- Department of Physics, Tulane University, New Orleans, Louisiana 70118, USA
| | - B. Heacock
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
| | - M. G. Huber
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J. Nsofini
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - D. A. Pushin
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - P. Saggu
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - D. Sarenac
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - C. B. Shahi
- Department of Physics, Tulane University, New Orleans, Louisiana 70118, USA
| | - V. Skavysh
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - W. M. Snow
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA
| | - A. R. Young
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
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Upadhye A. Symmetron dark energy in laboratory experiments. PHYSICAL REVIEW LETTERS 2013; 110:031301. [PMID: 23373910 DOI: 10.1103/physrevlett.110.031301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/19/2012] [Indexed: 06/01/2023]
Abstract
The symmetron scalar field is a matter-coupled dark energy candidate which effectively decouples from matter in high-density regions through a symmetry restoration. We consider a previously unexplored regime, in which the vacuum mass μ~2.4×10(-3) eV of the symmetron is near the dark energy scale, and the matter coupling parameter M~1 TeV is just beyond standard model energies. Such a field will give rise to a fifth force at submillimeter distances which can be probed by short-range gravity experiments. We show that a torsion pendulum experiment such as Eöt-Wash can exclude symmetrons in this regime for all self-couplings λ is < or approximately equal to 7.5.
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Affiliation(s)
- Amol Upadhye
- High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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Steffen JH, Upadhye A, Baumbaugh A, Chou AS, Mazur PO, Tomlin R, Weltman A, Wester W. Laboratory constraints on chameleon dark energy and power-law fields. PHYSICAL REVIEW LETTERS 2010; 105:261803. [PMID: 21231645 DOI: 10.1103/physrevlett.105.261803] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Indexed: 05/30/2023]
Abstract
We report results from a search for chameleon particles created via photon-chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of unexplored chameleon power-law and dark energy models. These results exclude 5 orders of magnitude in the coupling of chameleons to photons covering a range of 4 orders of magnitude in chameleon effective mass and, for individual models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.
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Affiliation(s)
- J H Steffen
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
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Rybka G, Hotz M, Rosenberg LJ, Asztalos SJ, Carosi G, Hagmann C, Kinion D, van Bibber K, Hoskins J, Martin C, Sikivie P, Tanner DB, Bradley R, Clarke J. Search for chameleon scalar fields with the axion dark matter experiment. PHYSICAL REVIEW LETTERS 2010; 105:051801. [PMID: 20867906 DOI: 10.1103/physrevlett.105.051801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 06/28/2010] [Indexed: 05/29/2023]
Abstract
Scalar fields with a "chameleon" property, in which the effective particle mass is a function of its local environment, are common to many theories beyond the standard model and could be responsible for dark energy. If these fields couple weakly to the photon, they could be detectable through the afterglow effect of photon-chameleon-photon transitions. The ADMX experiment was used in the first chameleon search with a microwave cavity to set a new limit on scalar chameleon-photon coupling βγ excluding values between 2×10(9) and 5×10(14) for effective chameleon masses between 1.9510 and 1.9525 μeV.
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Affiliation(s)
- G Rybka
- University of Washington, Seattle, Washington 98195, USA
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