Speaker
Description
The theoretical consideration of magnetic monopoles in astrophysical contexts introduces the possibility of their efficient acceleration to extreme energies by large-scale magnetic fields, a mechanism that could potentially produce Ultra-High-Energy (UHE) photons. However, there exists a theoretical argument, formulated within the quantum theory of the electric charge, that raises questions about the existence of magnetic monopoles. This argument, which may be of particular interest in the context of UHE photon searches, suggests that magnetic monopoles are unlikely to exist as isolated particles due to issues arising from the asymptotic structure of electromagnetic fields.
The argument hinges on the observation that information about electric and magnetic charges is encoded in the zero-frequency or infrared regime of the electromagnetic field. At spatial infinity, the electromagnetic field can be split into two massless scalar components: one representing the electric part and the other the magnetic part. However, the quantum mechanical treatment of these components reveals that the magnetic part would lead to negative norm states in the Hilbert space, violating the fundamental requirement of positivity in quantum mechanics.
This potential violation implies that the magnetic component, and thus magnetic monopoles, may not exist in isolation. Despite their possible realization in certain field-theoretical models, this argument challenges the theoretical foundation for the existence of magnetic monopoles. Given the current lack of empirical evidence and the identified theoretical inconsistencies, the status of magnetic monopoles in nature remains an intriguing and open question.
