Talk detail

Participant	Spallicci , Alessandro D.A.M.
Institution	Université d'Orléans - CNRS - CNRS-LPC2E 3A Av. Recherche Scientifique - Orléans - - France

Session	ED1	Accepted		Order	Time
Talk	Oral abstract	Title	Newtonian Free Fall Learnt at Youth, Now Revisited with an Einsteinian View
Coauthors
Abstract	Let us consider the legendary Pisa tower experiment in the Piazza del Miracoli by Galilei and ask ourselves if, neglecting air, stone size, Earth non-spherical shape and rotation, one kilogram stone falls like one of two kilograms. Young students spontaneously say no, often by a factor two or so, while teachers may say "exactly yes". Actually, they are both wrong. The right reply is "approximately yes" and depends on where we observe the fall. The difference between the two fall times is minuscule being of the order of the stone/Earth mass ratio, thus not yet measurable by state of the art technology. So why caring? We should care because it is not pedagogical to present approximations as exact and sacred laws of physics to digest as dogmas; because best students will remain puzzled by the superficiality and awkwardness of the explanations; because this ratio may take larger values and be of considerable influence in the Solar System. But especially because the heavier mass will fall faster or slower than the lighter one according to whether the observer is standing in the Piazza - that is at fixed distance from the Earth centre - or at a fixed distance from the joint (Earth and stone system) centre of mass. The physics dependency on the observer location appears in Newtonian classical mechanics, e.g. in collisions, de Coriolis force, and rises to feature of paramount significance in Einstein's general relativity.
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Session	PT4	Accepted		Order	Time
Talk	Oral abstract	Title	Photons in massive and non-linear theories
Coauthors
Abstract	Photons are the messengers from the Universe. Inexplicable observations on the latter prompt cosmologists to propose ingredients like dark matter, dark energy or the cosmological constant maintaining general relativity entirely valid, or else to propose alternatives to the non-linear theory of gravitation, namely general relativity, without evoking new ingredients. Confronted with this dichotomy, we consider legitimate also to investigate on the nature of the messengers, being the photon the sole massless particle of the Standard Model, and the waves emerging from a linear theory of the XIX century. Results on testing non-Maxwellian electromagnetism (either massive initiated by de Broglie and Proca or non-linear by Born and Infeld, Heisenberg and Euler) include setting photon mass upper limits from the modified AmpÃ¨reâ€™s law in solar wind through Cluster spacecraft [7], or from frequency dependent group velocities of photons from Fast Radio Bursts [2,5], and planned nanosatellites swarms operating in a new radio astronomy window, 10 KHz â€“ 10 MHz, [1]. An effective photon mass emerges when Super and Lorentz symmetries are broken, as well as [3]. Non-linear effects as polarisation dependent frequency shifts in strong magnetic field in Magnetars have been analysed too [6]. de Broglie formulated a photon mass already in 1922 and in the later year he estimated such mass to be lower than 10-53 kg, surprisingly close to the actual limits established by the Particle Data Group. Analysis of his work on the particle-wave duality will be a fundamental obligation in these studies. We are now completing our results in SuSy and Lorentz symmetry breaking where we find bi-refringence and dissipation and searching the conditions for photon mass and energy dissipation in a non-linear classic formalism. [1] Bentum M.J., Bonetti L., Spallicci A.D.A.M., 2017. Adv. Sp. Res., 59, 736. [2] Bonetti L., Ellis J., Mavromatos N.E., Sakharov A.S., Sarkisyan-Grinbaum E.K.G., Spallicci A.D.A.M., 2016. Phys. Lett. B, 757, 548. [3] Bonetti L., dos Santos Filho L.R., HelayÃ«l-Neto J.A., Spallicci A.D.A.M., 2017. Phys. Lett. B, 764, 203. [4] Bonetti L., dos Santos Filho L.R., HelayÃ«l-Neto J.A., Spallicci A.D.A.M., 2017. arXiv:1709.04995 [5] Bonetti L., Ellis J., Mavromatos N.E., Sakharov A.S., Sarkisyan-Grinbaum E.K.G., Spallicci A.D.A.M., 2017. Phys. Lett. B, 768, 326. [6] Bonetti L., Perez Bergliaffa S.E., Spallicci A.D.A.M., 2017, 14 M. Grossmann, World Scientific, arXiv:1610.05655 [astro-ph.HE]. [7] RetinÃ² A., Spallicci A.D.A.M., Vaivads A., 2016. Astropart. Phys., 82, 49.
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Session	PT6	Accepted		Order	Time
Talk	Oral abstract	Title	Space Experiments for the Foundations of Electromagnetism
Coauthors
Abstract	Testing the upper limit of the photon mass can be realised through the modified Ampere's law in solar wind, which we have realised with the Cluster spacecraft [2], or from frequency dependent group velocities with the proposed nanosatellites swarms operating in a new radio astronomy window, 10 KHz â€“ 10 MHz, [1]. Cluster and other upper limits appear in the Particle Data Group annual report. Finally, light frequency invariance in vacuum could be tested with the LISA interferometer. Incidentally, we ponder whether LISA could test the upper limit of the Hubble-Humason cosmological constant at small scale. [1] Bentum M.J., Bonetti L., Spallicci A.D.A.M., 2017. Adv. Sp. Res., 59, 736. [2] RetinÃ² A., Spallicci A.D.A.M., Vaivads A., 2016. Astropart. Phys., 82, 49.
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