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Federico Piazza

Federico Piazza's picture
APC, France

Area of Research:
Cosmology
Website: http://www.pariscosmo.fr/meet_new_pccp_fellow_federico_piazza.html
Phone: x7562

Research Interests

For many years advances in fundamental physics consisted in pushing the high energy limit of our knowledge higher and higher. In the last decade, cosmology has been flooded with such an amount of high precision data that a new, 'low energy path' to the mysteries of nature is now at hand. My research in cosmology focuses mainly on the two periods of accelerated expansion that our data strongly indicate and that are calling for a deeper understanding.

Inflation is an excellent low energy window on the highest energies. I worked on primordial non-gaussianities and models with varying speed of sound. I am very interested in fundamental aspects such as the relation between symmetries in inflationary theories and the almost scale invariance of the observed power spectrum.

Dark energy (the current acceleration of the universe), rather than just a low energy window seems to insinuate that some new unraveled physics is effective already at unexpectedly low energies. Such an amazing phenomenon may suggest that the standard low-energy framework `gravity+matter fields' is just inadequate and needs to be modified. I proposed an infrared modification of general relativity dictated by an 'ultra strong' version of the equivalence principle that seem to ease also other difficulties such as the cosmological constant problem and the black hole information paradox.

Violations of the (standard!) equivalence principle and gravitational phenomenology are another main branch of my research. I worked both on string-inspired model (the `runaway dilaton') and on simple scalar extension of the standard model (the 'higgs portal').

I also worked at the intersection between gravity and quantum information and considered regions of space as quantum subsystems as a way to generalize the standard framework of semi-classical gravity.

Positions Held

  • 2005 - 2006 Marie Curie Fellowship, Institute of Cosmology and Gravitation, University of Portsmouth.
  • 2003 - 2004 Post-doc, University of Milano Bicocca.

Awards

  • New Journal of Physics, Best of 2009: ``The IR-Completion of Gravity: What happens at Hubble Scales?'', F. Piazza, arXiv:0907.0765 [hep-th] New J. Phys. 11, 113050 (2009)
  • Honorable Mention at the Gravity Research Foundation essay competition 2009 with an essay of the title ``Modifying Gravity in the Infra-Red by imposing an 'Ultra-Strong' Equivalence Principle'', F. Piazza, Int. J. Mod. Phys. D 18, 2181 (2009) arXiv:0904.4299 [hep-th]

Recent Publications

Seminars

  • ``Modifying Gravity in the Infra-Red by imposing an Ultra-Strong equivalence principle" -- ``Emergent Gravity IV" August 24-28 2009, University of British Columbia, Vancouver (invited contribution) -- IHES, Paris, March 23, 2010 -- Imperial College, London, 16/12/2009 -- Department of Physics, University of Columbia, NY, 07/12/2009 -- CITA, Toronto, 30/10/2009 -- Department of Physics, University of Philadelphia, 09/09/2009 -- Department of Physics, University of Milan Bicocca, July 2009.
  • ``Scale invariant spectrum and rapidly varying speed of sound'' - PI-CITA day, Toronto, 19/5/2009 -- Workshop ``New Horizons for Modern Cosmology" Galileo Galilei Institute, Florence (Italy), 2/2/2009 -- talk given at ICG, Portsmouth, 15/1/2009
  • ``Regions of space as subsystems: entropy and semiclassical gravity'' -- ``DICE2008", Castiglioncello (Italy), September 22-26, 2008 -- "From Quantum to Emergent Gravity: Theory and Phenomenology", SISSA, Trieste, June 11-15, 2007
  • ``Particle detector models, thermal entropy and localization'' -- (String Theory-) Seminar, Department of Physics, UCB, Berkeley, September 9, 2008
  • ``Which space-time actually emerges? The world as seen from inside a spin system'' -- ``Emergent Gravity", MIT, Boston, August 25-29, 2008 (invited contribution)
  • ``Particle Detectors, the Frog Principle and the Unruh Effect'' -- ``Hot topics in Modern Cosmology" Cargese (Corse) May 12-17, 2008
  • PIRSA:08090054, Particle detector models, entropy and localization in semiclassical gravity, 2008-09-04, Quantum Gravity
  • PIRSA:08090060, Particle detector models, entropy and localization in semiclassical gravity, 2008-09-04, Quantum Gravity
  • PIRSA:08070013, Coupling variations and equivalence principle violations in string inspired scenarios, 2008-07-15, In Search for Variations of Fundamental Couplings and Mass Scales
  • PIRSA:08040072, Particle Detector Model Questions the Unruh Effect, 2008-04-30, Perimeter Institute Quantum Discussions
  • PIRSA:06010010, Spacetime regions as "quantum subsystems": glimmers of a pre-geometric perspective, 2006-01-19, Quantum Gravity
  • PIRSA:06010005, Gravity and cosmology of the dilaton at "strong coupling", 2006-01-17, Cosmology
  • PIRSA:04050000, Modifying Gravity in the Infra-Red by imposing an Ultra-Strong equivalence principle., 2004-05-27, New Prospects for Solving the Cosmological Constant Problem