# Evading equivalence principle violations, cosmological, and other experimental constraints in scalar field theories with a strong coupling to matter

## Abstract

We show that, as a result of nonlinear self-interactions, it is feasible, at least in light of the bounds coming from terrestrial tests of gravity, measurements of the Casimir force and those constraints imposed by the physics of compact objects, big-bang nucleosynthesis and measurements of the cosmic microwave background, for there to exist, in our Universe, one or more scalar fields that couple to matter much more strongly than gravity does. These scalar fields behave like chameleons: changing their properties to fit their surroundings. As a result these scalar fields can be not only very strongly coupled to matter, but also remain relatively light over solar-system scales. These fields could also be detected by a number of future experiments provided they are properly designed to do so. These results open up an altogether new window, which might lead to a completely different view of the role played by light scalar fields in particle physics and cosmology.

- Authors:

- Institute for Theoretical Physics, University of Heidelberg, 69120 Heidelberg (Germany)
- (Norway)
- (Canada)
- (United Kingdom)

- Publication Date:

- OSTI Identifier:
- 21020125

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevD.75.063501; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CASIMIR EFFECT; COSMOLOGY; EQUIVALENCE PRINCIPLE; GRAVITATION; NONLINEAR PROBLEMS; NUCLEOSYNTHESIS; QUANTUM FIELD THEORY; RELICT RADIATION; SCALAR FIELDS; SOLAR SYSTEM; STRONG-COUPLING MODEL; UNIVERSE

### Citation Formats

```
Mota, David F., Shaw, Douglas J., Institute of Theoretical Astrophysics, University of Oslo, N-0315, Oslopo, Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, and DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA.
```*Evading equivalence principle violations, cosmological, and other experimental constraints in scalar field theories with a strong coupling to matter*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.063501.

```
Mota, David F., Shaw, Douglas J., Institute of Theoretical Astrophysics, University of Oslo, N-0315, Oslopo, Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, & DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA.
```*Evading equivalence principle violations, cosmological, and other experimental constraints in scalar field theories with a strong coupling to matter*. United States. doi:10.1103/PHYSREVD.75.063501.

```
Mota, David F., Shaw, Douglas J., Institute of Theoretical Astrophysics, University of Oslo, N-0315, Oslopo, Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, and DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA. Thu .
"Evading equivalence principle violations, cosmological, and other experimental constraints in scalar field theories with a strong coupling to matter". United States.
doi:10.1103/PHYSREVD.75.063501.
```

```
@article{osti_21020125,
```

title = {Evading equivalence principle violations, cosmological, and other experimental constraints in scalar field theories with a strong coupling to matter},

author = {Mota, David F. and Shaw, Douglas J. and Institute of Theoretical Astrophysics, University of Oslo, N-0315, Oslopo and Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 and DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA},

abstractNote = {We show that, as a result of nonlinear self-interactions, it is feasible, at least in light of the bounds coming from terrestrial tests of gravity, measurements of the Casimir force and those constraints imposed by the physics of compact objects, big-bang nucleosynthesis and measurements of the cosmic microwave background, for there to exist, in our Universe, one or more scalar fields that couple to matter much more strongly than gravity does. These scalar fields behave like chameleons: changing their properties to fit their surroundings. As a result these scalar fields can be not only very strongly coupled to matter, but also remain relatively light over solar-system scales. These fields could also be detected by a number of future experiments provided they are properly designed to do so. These results open up an altogether new window, which might lead to a completely different view of the role played by light scalar fields in particle physics and cosmology.},

doi = {10.1103/PHYSREVD.75.063501},

journal = {Physical Review. D, Particles Fields},

number = 6,

volume = 75,

place = {United States},

year = {Thu Mar 15 00:00:00 EDT 2007},

month = {Thu Mar 15 00:00:00 EDT 2007}

}