https://doi.org/10.1140/epjc/s10052-019-6695-6
Regular Article - Theoretical Physics
Constraints on differential Shapiro delay between neutrinos and photons from IceCube-170922A
1
Department of Physics, Istanbul Technical University, Maslak, Istanbul, 34469, Turkey
2
Department of Physics, Indian Institute of Technology, Hyderabad, Telangana, 502285, India
* e-mail: borans@itu.edu.tr
Received:
1
October
2018
Accepted:
18
February
2019
Published online:
1
March
2019
On 22nd September 2017, the IceCube Collaboration detected a neutrino with energy of about 290 TeV from the direction of the gamma-ray blazar TXS 0506+056, located at a distance of about 1.75 Gpc. During the same time, enhanced gamma-ray flaring was also simultaneously observed from multiple telescopes, giving rise to only the second coincident astrophysical neutrino/photon observation after SN 1987A. We point out that for this event, both neutrinos and photons encountered a Shapiro delay of about 6300 days along the way from the source. From this delay and the relative time difference between the neutrino and photon arrival times, one can constrain violations of Einstein’s Weak Equivalence Principle (WEP) for TeV neutrinos. We constrain such violations of WEP using the Parameterized Post-Newtonian (PPN) parameter 
, which is given by 
, after assuming time difference of 175 days between neutrino and photon arrival times.
© The Author(s), 2019
