The orientation of polarization appears to be the most stable property of photons. However, changes in the polarization angle of photons traveling over cosmological distances are foreseen, for example, if fundamental physical principles, such as the Einstein Equivalence Principle, are violated.
The aim of this workshop is to get together theorists, who develop models leading to such cosmic polarization rotation (CPR), and experimentalists, who search for CPR using a variety of complementary methods, in order to discuss current results and future directions. The workshop will take place at the Villa Il Gioiello on the Arcetri hill near Florence, where Galileo, the first scientists to test the equivalence principle, spent the last 10 years of his life.
This Workshop is also in celebration of the Centennial of the theory of General Relativity, developed by Albert Einstein in 1915. In fact CPR has not yet been detected (current upper limits are of the order of 1 degree) and a null CPR results in a strong test of the Einstein Equivalence Principle, on which General Relativity is based. 2015 is also the International Year of Light.

Key Topics

- Models for CPR effects
- CPR phenomenology
- CPR searches with complementary methods
- Spacetime structure and Equivalence Principle tests
- Polarization angle calibration

Organizing Committee

Brian Keating (University of California San Diego, USA)
Jon Kaufman (University of California San Diego, USA)
Wei-Tou Ni (National Tsing Hua University, Taiwan, ROC)
Sperello di Serego Alighieri (INAF - Oss. di Arcetri, Firenze, Italy)

Local Support

Patrizia Braschi (INAF - Oss. di Arcetri, Firenze, Italy)


Osservatorio Astrofisico di Arcetri