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Depends very much on the boson and its interaction with the (extended) Standard Model that includes it. Axions, if they exist, take part in nuclear interaction

Depends very much on the boson and its interaction with the (extended) Standard Model that includes it. Axions, if they exist, take part in nuclear interactions. You can expect to have a bad day when encountering them at high density (e.g. expect fissions from neutron disruptions). In the preprint at the top, the Action (eqn (1)) and Lagrangian densities (eqn (2)) are non-interacting (except for self-interaction and gravitation) for tractability reasons, so the scalar boson version is only sorta like the axion. The paper's setting only considers each type of boson in isolation from any other type of matter in the universe. However any infalling body which has any nonzero distribution of these proposed vector or scalar bosons in them would expect the self-interaction term to be important, so you could still have a bad day for non-gravitational reasons. I don't think a non-relativistic analysis of a manifestly relativistic compact object is particularly enlightening. Boson stars can be more compact than neutron stars (see Figure 2 on p. 7 of the preprint). Qualitatively though, you'd have a bad day if you got too close; you are right that tidal stresses are probably what will get you in the case of only-self-interacting bosons. The Roche limit, developed well before even special relativity, matters for slowly-orbiting (hyperbolic orbits count) self-gravitating bodies (so big asteroids and comets count). Your parent commentator's flight would presumably be in a spacecraft (or suit) that is held together by intermolecular forces instead of its own gravity. Those forces are typically much stronger than gravity; gravity only overcomes them in relativistic systems.

NoMoreNicksLeft 3y ago
Wait. So there's not even a model of which bosons we're talking about? I'd seen the wikipedia a few years back, and I assumed it was just light on details because it's wikipedia.
- raattgift 3y ago
  There are dozens, scores, and likely hundreds of different (hypothetical) bosons described as the sole (or at least dominant) matter in a boson star (cf. link at the end of this comment). In the preprint linked at the top I count at least sixteen different specific (hypothetical) bosons in their References section, and the preprint discusses two very broad families (in §2). The authors' claim is that a wide variety of (massive) boson theories can in bulk behaviour produce the important characteristics of a boson star constrained by what they know of this particular binary (see end of 1st paragraph of §6). > assumed it was just light on details because it's wikipedia An encyclopedic overview should probably not point to every paper one would get from a search of the literature, let alone to a search of preprints. Wikipedia is likely light on details because the topic is niche because it's an idea which is nowhere near as convincing as perturbations of black hole solutions of the Einstein Field Equations ("standard black holes"), and not even more persuasive than e.g. fuzzballs, gravastars, and other relativistic dark star hypotheses also aiming to overthrow standard black holes for various reasons. Even the list of reasons for studying just boson stars gets long: because the compact object may be dominated by a particle that might solve problems in particle physics (but which would be hard to prove/disprove in an Earthbound lab soon); or that might also describe dark matter and/or dark energy; or that (if observed) would support a broader theory like M-theory; or that might put to bed any questioning of unitarity; ... And because some types of boson stars (if found in nature) might support one of these broader aims to the exclusion of the other aims, it's a somewhat busy field with papers and anti-papers. Here's a couple hundred: <https://arxiv.org/search/?query=%22boson+star%22&searchtype=all&abstracts=show&order=-announced_date_first&size=50 https://arxiv.org/search/?query=%22boson+star%22&searchtype=...>

NoMoreNicksLeft 3y ago

Wait. So there's not even a model of which bosons we're talking about? I'd seen the wikipedia a few years back, and I assumed it was just light on details because it's wikipedia.

raattgift 3y ago
There are dozens, scores, and likely hundreds of different (hypothetical) bosons described as the sole (or at least dominant) matter in a boson star (cf. link at the end of this comment). In the preprint linked at the top I count at least sixteen different specific (hypothetical) bosons in their References section, and the preprint discusses two very broad families (in §2). The authors' claim is that a wide variety of (massive) boson theories can in bulk behaviour produce the important characteristics of a boson star constrained by what they know of this particular binary (see end of 1st paragraph of §6). > assumed it was just light on details because it's wikipedia An encyclopedic overview should probably not point to every paper one would get from a search of the literature, let alone to a search of preprints. Wikipedia is likely light on details because the topic is niche because it's an idea which is nowhere near as convincing as perturbations of black hole solutions of the Einstein Field Equations ("standard black holes"), and not even more persuasive than e.g. fuzzballs, gravastars, and other relativistic dark star hypotheses also aiming to overthrow standard black holes for various reasons. Even the list of reasons for studying just boson stars gets long: because the compact object may be dominated by a particle that might solve problems in particle physics (but which would be hard to prove/disprove in an Earthbound lab soon); or that might also describe dark matter and/or dark energy; or that (if observed) would support a broader theory like M-theory; or that might put to bed any questioning of unitarity; ... And because some types of boson stars (if found in nature) might support one of these broader aims to the exclusion of the other aims, it's a somewhat busy field with papers and anti-papers. Here's a couple hundred: <https://arxiv.org/search/?query=%22boson+star%22&searchtype=all&abstracts=show&order=-announced_date_first&size=50 https://arxiv.org/search/?query=%22boson+star%22&searchtype=...>