Gravitationsinduzierter Kollaps der Wellenfunktion und experimentelle Tests

• Antragsteller: Dr. André Großardt
• Fachliche Zuordnung: Kern- und Elementarteilchenphysik, Quantenmechanik, Relativitätstheorie, Felder
• Förderung: Förderung von 2014 bis 2016
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 266142017

• Erstellungsjahr: 2017

Zusammenfassung der Projektergebnisse

Whether or not the gravitational field must be described by a quantum theory, similar to the other three fundamental interactions, or behaves differently—in a fundamentally classical way—at the microscopic level, is still an unresolved question. The research project “Gravity-induced wave-function collapse and experimental tests” aimed at studying experimentally testable consequences of the second possibility, and the potential connection of this possibility to another big unresolved question of fundamental physics: how the “collapse” of quantum wave-functions occurs, or how our classical world emerges from the principles of quantum physics. The subject of these studies is the so-called Schrödinger-Newton equation, a nonlinear modification of the Schrödinger equation which describes the evolution of a quantum wave-function, but also contains a term that corresponds to the wave-function attracting itself due to gravitational influences. In the course of this research project, in collaboration with experimental physicists at the University of Southampton, a new effect was found, that due to this gravitational self-influence the energy spectrum of a particle trapped in an electromagnetic field will be distorted. This effect promises to provide a more feasible way to test the Schrödinger-Newton equation than previous proposals. Further outcomes of the project are a more efficient way of calculating the time evolution of a free particle which is subject to a gravitational self-interaction, which could turn out to be helpful for the design of experimental tests in a satellite mission, as well as a better understanding of the difficulties arising when trying to incorporate the Schrödinger-Newton equation into the physics of a specific class of heavy elementary particles, so-called neutral mesons. Research is still ongoing on links of the Schrödinger-Newton equation to the equations that describe light propagating through an optical fibre, which may result in fruitful new insights about both the gravitational and the optical systems.

Projektbezogene Publikationen (Auswahl)

• Newtonian self-gravitation in the neutral meson system. Phys. Rev. D, 91, 064056 (2015)
  Großardt, André & Hiesmayr, Beatrix C.
  
• Approximations for the free evolution of self-gravitating quantum particles. Phys. Rev. A, 94, 022101 (2016)
  Großardt, André
  
• Effects of Newtonian gravitational self-interaction in harmonically trapped quantum systems. Sci. Rep., 6, 30840 (2016)
  Großardt, André; Bateman, James; Ulbricht, Hendrik & Bassi, Angelo
  
• Optomechanical test of the Schrödinger– Newton equation. Phys. Rev. D, 93, 096003 (2016)
  Großardt, André; Bateman, James; Ulbricht, Hendrik & Bassi, Angelo
  
• (2017) Gravitational decoherence. Class. Quantum Grav. (Classical and Quantum Gravity) 34 (19) 193002
  Bassi, Angelo; Großardt, André & Ulbricht, Hendrik