Gravitational blueshift from a collapsing object

Lingyao Kong, Daniele Malafarina, Cosimo Bambi

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


We discuss a counterintuitive phenomenon of classical general relativity, in which a significant fraction of the radiation emitted by a collapsing object and detected by a distant observer may be blueshifted rather than redshifted. The key-point is that when the radiation propagates inside the collapsing body, it is blueshifted, and this time interval may be sufficiently long for the effect to be larger than the later redshift due to the propagation in the vacuum exterior, from the surface of the body to the distant observer. Unfortunately, the phenomenon can unlikely have direct observational implications, but it is interesting by itself as a pure relativistic effect.

Original languageEnglish
Pages (from-to)82-86
Number of pages5
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Publication statusPublished - Feb 4 2015

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Fingerprint Dive into the research topics of 'Gravitational blueshift from a collapsing object'. Together they form a unique fingerprint.

Cite this