Ellipticity weakens chameleon screening

@article{Burrage2014EllipticityWC,
  title={Ellipticity weakens chameleon screening},
  author={Clare Burrage and Edmund J. Copeland and James A. Stevenson},
  journal={Physical Review D},
  year={2014},
  volume={91},
  pages={065030}
}
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… 
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References

SHOWING 1-10 OF 32 REFERENCES

Tuning the mass of chameleon fields in Casimir force experiments.

The gas in the gap weakens the chameleon interaction mechanism with a screening effect that increases with the plate separation and with the density of the intervening medium.

Screening long-range forces through local symmetry restoration.

A screening mechanism that allows a scalar field to mediate a long-range force of gravitational strength in the cosmos while satisfying local tests of gravity and predicting deviations from general relativity in the solar system that are within reach of next-generation experiments, as well as astrophysically observable violations of the equivalence principle.

Chameleons in the early Universe: Kicks, rebounds, and particle production

Chameleon gravity is a scalar-tensor theory that includes a nonminimal coupling between the scalar field and the matter fields and yet mimics general relativity in the Solar System. The scalar degree…

Quantum stability of chameleon field theories.

An improvement of less than a factor of two in the range of fifth force experiments could test all classical chameleon field theories whose quantum corrections are well controlled and couple to matter with nearly gravitational strength regardless of the specific form of the Chameleon potential.

No-go theorems for generalized chameleon field theories.

It is proved two theorems limiting its cosmological impact: the Compton wavelength of such a scalar can be at most ~/= 1 MPc at the present cosmic density, which restricts its impact to nonlinear scales, and the conformal factor relating Einstein- and Jordan-frame scale factors is essentially constant over the last Hubble time, which precludes the possibility of self-acceleration.

Detecting chameleon dark energy via an electrostatic analogy.

It is shown that nonspherical test bodies immersed in a background field will experience a net torque caused by the scalar field, and Interestingly, the field demonstrates a "lightning rod" effect, where it becomes enhanced near the ends of a pointed or elongated object.

Detecting chameleons through Casimir force measurements

The best laboratory constraints on strongly coupled chameleon fields come not from tests of gravity per se but from precision measurements of the Casimir force. The chameleonic force between two…

Shape dependence of Vainshtein screening

Scalar field theories that possess a Vainshtein mechanism are able to dynamically suppress the associated fifth forces in the presence of massive sources through derivative nonlinearities. The…

Catastrophic consequences of kicking the chameleon.

It is demonstrated that quantum particle production can profoundly affect scalar-tensor gravity, a possibility not previously considered, and developed the theory and numerics of particle production in the regime of strong dissipation.

Strongly coupled chameleons and the neutronic quantum bouncer.

It is shown that the presence of a chameleon field over a planar plate would alter the energy levels of ultracold neutrons in the terrestrial gravitational field.