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Do observations of black hole candidates rule out alternative theories ofgravity without horizon formation? This depends on the existence, viability andreasonableness of alternative theories of gravity without black holes.  Here a theory of gravity without black hole horizon formation is presented.The gravitational collapse stops shortly before horizon formation and leaves astable frozen star. In the limit $\Xi, \Upsilon\to 0$ the Einstein equations ofGR are recovered, and the frozen stars become observationally indistinguishablefrom GR black holes. The theory therefore provides a counterexample to recentclaims that observational evidence from black hole candidates "all but requiresthe existence of a horizon".  The theory presented here shares its equations with RTG. Nonetheless, as isshown, there remain important conceptual and physical differences. Inparticular, some serious problems of RTG are not present in the theory proposedhere. So it can be argued that the theory is a physically viable andconceptually sound alternative to GR.

Black Holes or Frozen Stars? A Viable Theory of Gravity without Black Holes