Chameleon fragmentation

Boom Chameleon

We introduce the Boom Chameleon, a novel input/output device consisting of a flat-panel display mounted on a tracked mechanical boom. The display acts as a physical window into 3D virtual environments, through which a one-to-one mapping between real and virtual space is preserved. The Boom Chameleon is further augmented with a touch-screen and a microphone/speaker combination. We present a 3D a...

Chameleon Signatures

Tests of chameleon gravity

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 the...

Beyond the Chameleon Mechanism

As a result of non-linear self-interactions, in chameleon theories where the field couples to matter much more strongly than gravity does, the fifth force between two bodies with thinshell is independent of their coupling to the field. As a consequence the bounds on the coupling coming from terrestrial tests of gravity, measurements of the Casimir force and those constraints imposed by the phys...

Chameleon Vector Bosons

We show that for a force mediated by a vector particle coupled to a conserved U(1) charge, the apparent range and strength can depend on the size and density of the source, and the proximity to other sources. This “chameleon” effect is due to screening from a light charged scalar. Such screening can weaken astrophysical constraints on new gauge bosons. As an example we consider the constraints ...