Solar wind test of the de Broglie-Proca's massive photon with Cluster multi-spacecraft data

Understand

Our understanding of the universe at large and small scales relies largely on electromagnetic observations.

• As photons are the messengers, fundamental physics has a concern in testing their properties, including the absence of mass.
• We use Cluster four spacecraft data in the solar wind at 1 AU to estimate the mass upper limit for the photon.
• We look for deviations from Amp\`ere's law, through the curlometer technique for the computation of the magnetic field, and through the measurements of ion and electron velocities for the computation of the current.