Till innehåll på sidan

Testing Extended Theories of Electromagnetism with MMS data

Tid: On 2022-09-28 kl 13.15

Plats: Gustaf Dahlander

Videolänk: https://kth-se.zoom.us/j/61051297962

Föreläsare: Alessandro D.A.M. Spallicci, Université d’Orléans

Astrophysical observations are largely based on electromagnetic signals still read with the Maxwellian massless and linear theory, possibly an approximation of a larger theory, as Newtonian gravity is for the Einsteinian gravity in weak fields. Photons are the sole free massless particles in the Standard-Model (SM). Apart from massive formalisms (de Broglie-Proca, Bopp, Stueckelberg and others), the SM Extension dresses the photon of a mass dependent from the Lorentz-Poincaré symmetry violation. Non-linear theories (Euler-Heisenberg for second order quantum electrodynamics and strong magnetic fields, Born-Infeld for normalising the infinitesimal charge and followers) complete the picture of the Extended Theories of Electromagnetism (ETE). Adopting ETE leads to surprising options for reading the universe and to challenges to the ΛCDM cosmology, e.g., light dispersion with a bearing on multi-messenger astronomy, photon frequency shift in vacuo with a bearing on the red shift and dark energy. Pursuing another line of investigation, we have applied the Heisenberg principle at cosmological scales. We have identified an intrinsic limit to the measurement of the velocity of the expansion. This limit stands behind the Hubble tension and the Hubble-Lemaître expansion parameter emerges as quantum measurement.
In this seminar we focus on deviations from the Ampère-Maxwell law, due to an ETE contribution, which. were sought in six years of MMS satellite data (3.8 million points). Our results can be summarised as follows: in most cases the curl current is consistent with the particle current and thereby we can set an upper limit to the deviations, but in a very minority of cases, mostly in the solar wind, we find an inequality between the two currents even when including the errors, being the displacement current order of magnitude smaller than the inequality. Future satellite measurements may clarify the nature of these deviations, whether unaccounted errors or profoundly meaningful results. This investigation affirms the pivotal role that solar plasma physics could play for fundamental physics investigations and how the latter may push instrument developers to ultimate metrological performances.
These works in theory, observations and experiments come from a collaboration with CERN-King’s College London, Univ. Napoli, UERJ and CBPF Rio de Janeiro, IAC Tenerife and other institutes.

Innehållsansvarig:Tomas Karlsson
Tillhör: Rymd- och plasmafysik
Senast ändrad: 2022-09-22