What exactly is a "conclusive association" in Astronomy?
A &quot;conclusive association&quot; is an oxymoron; for example, &quot;brawling love&quot;, &quot;loving hate&quot; (these first two are from Shakespeare), &quot;act naturally&quot;, or &quot;jumbo shrimp&quot;. An association is a vague term while conclusive is very specific and means proven without a doubt.
The underlying journal article does not claim the authors have provided a &quot;conclusive association between the diffuse gas in the space between galaxies and the large-scale structure of the cosmic web predicted by cosmological theory.&quot; That is what the press release claims. Press releases are not subject to peer review. Press releases can, and oftentimes do, use over flowery speech.
The underlying journal article does claim that &quot;statistics of absorption by the intergalactic medium (IGM) via spectroscopy of distant quasars support the model yet have not conclusively tied the diffuse IGM to the web.&quot; This is true. The implication is that the authors' model has conclusively tied the diffuse IGM to the web. The author do not explicitly make this claim in the journal paper. Suppose the authors had make this claim in early versions of the paper. If that was the case, peer reviewers would inevitably have said to remove this claim on the basis that &quot;conclusive&quot; is an extremely strong word in science.
Even if peer review had allowed that claim, it would still be dubious. Many scientific press releases claim that the research being reported is ground shaking and conclusive. Don't take press releases as fact. Only a tiny few scientific papers show something that is ground shaking and conclusive. Those that do do so (e.g., Einstein's annus mirabilis papers) are very few and very far between.