Here’s a round-up of maths news stories from this month we haven’t otherwise covered on the Aperiodical (not including, of course, the important enneahedron news Christian just posted about).

MathJax, a Javascript display engine for typesetting maths in LaTeX, has released their latest new version, v4.0. It has more new fonts, better accessibility, line-breaking support, HTML inside maths expressions, and lots more new features.

A convex polyhedron without the Rupert property has been discovered (video above). The Rupert property, named after Prince Rupert’s cube, which famously has it, means that an exact copy of the shape can be passed through the original shape in some direction without touching the sides. For a cube, this happens diagonally through one of the corners, and until recently it had been conjectured that all convex polyhedra have this property (and also separately conjectured by someone else that that the rhombicosidodecahedron does not have it). The first of of these has now been disproven, and the newly discovered shape has been adorably termed a Noperthedron.

There’s also been knot theory news, in that it’s been proven by Mark Brittenham and Susan Hermiller that the unknotting number (the number of crossings you need to flip to make something the unknot) is not additive under connected sum of knots. The discovery involves the example of the \(7_1\) torus knot, which when put beside its own chiral opposite knot and added together (shown above), creates a knot whose unknotting number is less than the sum of the unknotting numbers of the two individual knots. This hasn’t previously been observed, and the exciting news has been expertly written up in this Scientific American post). (via Ian Agol)

(If you’d like to hear Katie waffle on about both of these recent findings, as well as some maths hiding in other science news, we can recommend this episode of BBC Inside Science from earlier in the month).

And in other news, the LMS has published a statement of commitment for trans inclusion. The statement “solidifies the LMS’s commitment to protecting the rights and promoting the inclusion of trans and nonbinary mathematicians.” You can read the full PDF on the LMS website.