Over the years, the so-called black hole information loss paradox has generated an amazingly diverse set of proposals. However, 40 years after the introduction of Hawking’s radiation, there continues to be a debate regarding whether the effect does, in fact, lead to an actual problem. In this paper we try to clarify some aspect of the discussion by describing two possible perspectives regarding the landscape of the information loss issue. Moreover, we advance a fairly conservative point of view regarding the (...) relation between evaporating black holes and the rest of physics, which leads us to advocate a generalized breakdown of unitarity. We conclude by exploring some implications of our proposal in relation with conservation laws. (shrink)

The information loss paradox is often presented as an unavoidable consequence of well-established physics. However, in order for a genuine paradox to ensue, not-trivial assumptions about, e.g., quantum effects on spacetime, are necessary. In this work we will be explicit about these additional, speculative assumptions required. We will also sketch a map of the available routes to tackle the issue, highlighting the, often overlooked, commitments demanded of each alternative. Finally, we will display the strong link between black holes, the issue (...) of information loss and the measurement problem. (shrink)

In the science fiction novel Quarantine, Greg Egan imagines a universe where interactions with human observers collapse quantum wavefunctions. Aliens, unable to collapse wavefunctions, tire of being slaughtered by these collapses. In response they erect an impenetrable shield around the solar system, protecting the rest of the universe from human interference and locking humanity into a starless Bubble. When confronting scientific realism and the quantum, many philosophers try to do the theoretical counterpart of this fictional practical strategy. Quantum mechanics is (...) beset with many hard-to-resolve interpretational challenges. Philosophers — appealing to decoherence and coarse-graining — try to put these in a bubble and hope that they can go about their philosophizing as before. My chapter aims to burst this Bubble. (shrink)

We put forward a proposal that combines objective collapse models, developed in connection with quantum-foundational questions, with the so-called Weyl curvature hypothesis, introduced by Roger Penrose as an attempt to account for the very special initial state of the universe. In particular, we explain how a curvature dependence of the collapse rate in such models, an idea already shown to help in the context of black holes and information loss, could also offer a dynamical justification for Penrose's conjecture.

Inspired by possible connections between gravity and foundational question in quantum theory, we consider an approach for the adaptation of objective collapse models to a general relativistic context. We apply these ideas to a list of open problems in cosmology and quantum gravity, such as the emergence of seeds of cosmic structure, the black hole information issue, the problem of time in quantum gravity and, in a more speculative manner, to the nature of dark energy and the origin of the (...) very special initial state of the universe. We conclude that objective collapse models offer a rather promising path to deal with all of these issues. (shrink)