Fundamental quantum optics experiments conceivable with satellites -- reaching relativistic distances and velocities

Physical theories are developed to describe phenomena in particular regimes, and generally are valid only within a limited range of scales. For example, general relativity provides an effective description of the Universe at large length scales, and has been tested from the cosmic scale down to distances as small as 10 meters. In contrast, quantum theory provides an effective description of physics at small length scales. Direct tests of quantum theory have been performed at the smallest probeable scales at the Large Hadron Collider, ${\sim} 10^{-20}$ meters, up to that of hundreds of kilometers. Yet, such tests fall short of the scales required to investigate potentially significant physics that arises at the intersection of quantum and relativistic regimes. We propose to push direct tests of quantum theory to larger and larger length scales, approaching that of the radius of curvature of spacetime, where we begin to probe the interaction between gravity and quantum phenomena. In particular, we review a wide variety of potential tests of fundamental physics that are conceivable with artificial satellites in Earth orbit and elsewhere in the solar system, and attempt to sketch the magnitudes of potentially observable effects. The tests have the potential to determine the applicability of quantum theory at larger length scales, eliminate various alternative physical theories, and place bounds on phenomenological models motivated by ideas about spacetime microstructure from quantum gravity. From a more pragmatic perspective, as quantum communication technologies such as quantum key distribution advance into Space towards large distances, some of the fundamental physical effects discussed here may need to be taken into account to make such schemes viable.Comment: 34 pages, 9 figures. Journal version, modified to respond to numerous suggestion

Monsters in the Dark: High Energy Signatures of Black Hole Formation with Multimessenger Astronomy

When two compact objects inspiral and violently merge it is a rare cosmic event, producing fantastically “luminous” gravitational wave emission. It is also fleeting, staying in the Laser Interferometer Gravitational-wave Observatory’s (LIGO) sensitive band only for somewhere between tenths of a second and several tens of minutes. However, when there is at least one neutron star, disk formation during the merger may power a slew of potentially detectable electromagnetic counterparts, such as short gamma-ray bursts (GRBs), afterglows, and kilonovae. These explosions span the full electromagnetic spectrum and are expected within seconds, hours or days of the merger event. To learn as much astrophysics as possible requires targeted observations at every stage of this process, demanding a coordinated worldwide effort across many facilities and multiple astronomical disciplines, all in nearly real-time. In this dissertation I outline some of the major obstacles facing the multimessenger astronomy effort, including computation, data analysis and sky localization for LIGO source candidates, as well as disseminating this information quickly to the astronomical community. I also report on the performance of some of these services during Advanced LIGO’s first Observing Run, and on my experience at LIGO Livingston Observatory during the first Observing Run of LIGO’s Advanced stage, during which the instruments directly detected gravitational waves for the very first time. (The transient source GW150914 was observed 14 September 2015, and is consistent with a binary black hole merger at redshift 0.09.) I also participate in time-domain optical astronomy with the intermediate Palomar Transient Factory (iPTF) collaboration, searching for orphaned afterglow candidates to better understand the nature of relativistic outbursts such as GRBs

Testing the nature of dark compact objects: a status report

Very compact objects probe extreme gravitational fields and may be the key to understand outstanding puzzles in fundamental physics. These include the nature of dark matter, the fate of spacetime singularities, or the loss of unitarity in Hawking evaporation. The standard astrophysical description of collapsing objects tells us that massive, dark and compact objects are black holes. Any observation suggesting otherwise would be an indication of beyond-the-standard-model physics. Null results strengthen and quantify the Kerr black hole paradigm. The advent of gravitational-wave astronomy and precise measurements with very long baseline interferometry allow one to finally probe into such foundational issues. We overview the physics of exotic dark compact objects and their observational status, including the observational evidence for black holes with current and future experiments.Comment: 76 pages + references. Invited review article for Living Reviews in Relativity. v3: Overall improvements and references added, a few typos corrected. Version to appear in LR

A teaching/learning path on the concept of mass and mass-energy relationship for upper secondary school

A content-oriented research on the fundamental physics concept of mass and mass-energy relationship was carried out, according to the tenets of Design-based Research and adopting the Model of Educational Reconstruction. The classical and special-relativistic meanings of mass were reconstructed through a vertical approach, by exploiting a \uabhistorical line\ubb. This brought to design two teaching/learning paths, which were iteratively tested and revised by 14 formative intervention experiments in upper secondary school. Inquiry-based Learning, visualization, WTL strategy, RTEI (POE, PEC), \uabcollective reasoning\ubb by interactive/dialogic and interactive/authoritative discourse were used, together with innovative educational materials. Students\u2019 learning process was locally and globally studied by analysing conceptual change, learning pathways and reasoning profiles.\uc8 stata condotta una ricerca specifica sul concetto fisico fondamentale di massa e sulla relazione massa-energia, secondo i principi della Design-based Research e adottando il Model of Educational Reconstruction. I significati di massa in fisica classica e relativit\ue0 ristretta sono stati ricostruiti attraverso un approccio verticale, utilizzando una \uablinea storica\ubb. Ci\uf2 ha portato a progettare due percorsi di insegnamento/apprendimento, che sono stati testati e modificati iterativamente attraverso 14 sperimentazioni didattiche nella scuola secondaria superiore. Sono stati utilizzati Inquiry-based Learning, visualizzazione, strategia WTL, RTEI (POE, PEC), ragionamento collettivo tramite conversazioni interattivo/autoritarie e interattivo/dialogiche, assieme a materiali didattici innovativi (in particolare esperimenti mentali). Il processo di apprendimento degli studenti \ue8 stato studiato globalmente e localmente analizzando il cambio concettuale, i percorsi di apprendimento e i profili di ragionamento