Niles Johnson<p>New paper 🎉🎉<br />About coherence 🥱💤⁉️</p><p>joint work with Nick Gurski<br /><a href="https://arxiv.org/abs/2312.11261" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://</span><span class="">arxiv.org/abs/2312.11261</span><span class="invisible"></span></a></p><p>The title is:<br />Universal pseudomorphisms, [*deep breath*]<br />with applications to diagrammatic coherence for braided and symmetric monoidal functors 🙃😸</p><p>I've always thought coherence theorems sound boring, but actually they're good! In this paper we take a problem that is hard (coherence for structured functors), do a *bunch* of really abstract stuff (2-monad theory), and come out with a solution that makes your life* significantly better.</p><p>[*Here, "your life" means the part of your life you spend checking diagrams of braided monoidal functors. Or, more generally, pseudomorphisms for algebras over a 2-monad.]</p><p>Almost 1/5 of this paper is dedicated to real, genuine examples, and that's what I want to focus on below. I'll say just a bit about the more abstract machinery on which the examples are based. If you've been following along, this is the culmination of my series "weird facts about monoidal functors and coherence" [1,2,3,4].</p><p>[1] <a href="https://mathstodon.xyz/@nilesjohnson/110741323263984146" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://</span><span class="ellipsis">mathstodon.xyz/@nilesjohnson/1</span><span class="invisible">10741323263984146</span></a><br />[2] <a href="https://mathstodon.xyz/@nilesjohnson/110876487813747736" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://</span><span class="ellipsis">mathstodon.xyz/@nilesjohnson/1</span><span class="invisible">10876487813747736</span></a><br />[3] <a href="https://mathstodon.xyz/@nilesjohnson/110979458364785667" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://</span><span class="ellipsis">mathstodon.xyz/@nilesjohnson/1</span><span class="invisible">10979458364785667</span></a><br />[4] <a href="https://mathstodon.xyz/@nilesjohnson/111070640771166081" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://</span><span class="ellipsis">mathstodon.xyz/@nilesjohnson/1</span><span class="invisible">11070640771166081</span></a></p><p><a href="https://mathstodon.xyz/tags/CategoryTheory" class="mention hashtag" rel="tag">#<span>CategoryTheory</span></a> <a href="https://mathstodon.xyz/tags/MonoidalFunctor" class="mention hashtag" rel="tag">#<span>MonoidalFunctor</span></a> <a href="https://mathstodon.xyz/tags/Coherence" class="mention hashtag" rel="tag">#<span>Coherence</span></a> <a href="https://mathstodon.xyz/tags/Braided" class="mention hashtag" rel="tag">#<span>Braided</span></a> <a href="https://mathstodon.xyz/tags/Symmetric" class="mention hashtag" rel="tag">#<span>Symmetric</span></a> <a href="https://mathstodon.xyz/tags/PseudomorphismClassifier" class="mention hashtag" rel="tag">#<span>PseudomorphismClassifier</span></a></p><p>(1/14)</p>