Constraints on vector unparticle physics from cosmic censorship

Vector unparticle couplings to standard model fields produce repulsive corrections to gravity. From a general relativistic perspective, this leads to an effective Reissner-Nordström-like metric whose "charge" is a function of the unparticle coupling constant $λ$, and therefore can admit naked singularities. Requiring the system to respect cosmic censorship provides a new method of constraining the value of $λ$. These limits are extremely loose for stellar-mass black holes, but commensurate with existing bounds for primordial black holes. In the case of theoretical low-mass black holes, the bounds on $λ$ are much stricter than those derived from astrophysical and accelerator phenomenology. Additional constraints on the lower limit of $λ$ are used to estimate the mass of the smallest possible black hole $\Mbh^{\rm min}$ that can be formed in the unparticle framework, as a function of the unparticle parameters ($Λ_\unp,M_\unp,\du,\dbz$).

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