Paper “Photon Absorption in a Doubly Special Relativity Model with Undeformed Free Propagation and Total Momentum Conservation” (DOI: 10.1088/1475-7516/2025/07/066) was published in Journal of Cosmology and Astroparticle Physics. The authors are J. M. Carmona, J. L. Cortés, F. Reščić, M. A. Reyes, and T. Terzić. The paper can also be found in ArXiv: 2503.15203.

In doubly special relativity (DSR), unlike in Lorentz invariance violation (LIV), there is no privileged reference frame, but the conservation laws of particle interactions are deformed. The lack of a dynamical framework has so far prevented a phenomenology of modified interactions in DSR. In this work we show that, in a model based on the classical basis of κ-Poincaré with total momentum conservation, the cross section of photon-photon pair production is well defined once a prescription for treating the different interaction channels is set. The modified interaction can produce observable effects on the transparency of the Universe to gamma rays whose energy approaches the energy scale of the deformation.

This is the second paper of the collaboration between the University of Rijeka and the University of Zaragoza, following Carmona et al. (2024).

Paper abstract: The lack of a dynamical framework within doubly special relativity theories has impeded the development of a corresponding phenomenology of modified interactions. In this work we show that in a model based on the classical basis of κ-Poincaré and total momentum conservation, one has a well-defined cross section of the photon-photon annihilation process, once a prescription for the channel treatment is set. The modification of the interaction can lead to observable effects in the opacity of the Universe to very high-energy gamma rays when the gamma-ray energy approaches the energy scale of the deformation. The magnitude and observability of this deformation are examined as functions of the gamma-ray energy and source distance.