# Emission of Cosmic Radio-waves, $X$- or $\\gamma$-rays by Moving Unstable Particles at Late Times Source: [Emission of Cosmic Radio-waves, $X$- or $\\gamma$-rays by Moving Unstable Particles at Late Times]() Collection index: [llms.txt]() Data updated: 2025-10-28T13:53:26.920Z Authors: K. Urbanowski Published: 2015-02-11T17:56:49.000Z ## Abstract A new quantum effect connected with the late time behavior of decaying states is described and its possible observational consequences are analyzed: It is shown that charged unstable particles as well as neutral unstable particles with non--zero magnetic moment which live sufficiently long may emit electromagnetic radiation. This mechanism is due to the nonclassical behavior of unstable particles at late times (at the post exponential time region). Analyzing the transition times region between exponential and non-exponential form of the survival amplitude it is found that the instantaneous energy of the unstable particle can take very large values, much larger than the energy of this state at times from the exponential time region. Based on the results obtained for the model considered, it is shown that this new purely quantum mechanical effect may be responsible for causing unstable particles produced by astrophysical sources and moving with relativistic velocities to emit electromagnetic--, $X$-- or $\\gamma$--rays at some time intervals from the transition time regions. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. ## Original sources and implementation [Original paper]() [PDF]()