In one of my lectures today we paused at the term abelian and noted that it is an incredibly high honor to have an adjective with the first letter uncapitalized (apparently other countries leave the first letter capitalized) based on one's name. Other than abelian, the only other examples that were mentioned were noetherian and artinian. Are there other examples?
Hermitian is an example: those matrices whose inverse is its conjugate transpose.
Of course, many objects bear mathematicians' names alone just as an adjective (see Duncan's example on topological spaces). We also have Eulerian paths and Hamiltonian circuits, as well as Lagrangian interpolating polynomials.
When I first learned abstract algebra I wondered what ethers were that a noetherian ring had none of. (Later I was on the faculty at Bryn Mawr where a colleague used Emmy Noether's desk.)
And of course there's "algorithm":
The words 'algorithm' and 'algorism' come from the name al-Khwārizmī. Al-Khwārizmī (Persian: خوارزمی, c. 780–850) was a Persian mathematician, astronomer, geographer, and scholar in the House of Wisdom in Baghdad, whose name means 'the native of Khwarezm', a region that was part of Greater Iran and is now in Uzbekistan. About 825, he wrote a treatise in the Arabic language, which was translated into Latin in the 12th century under the title Algoritmi de numero Indorum. This title means "Algoritmi on the numbers of the Indians", where "Algoritmi" was the translator's Latinization of Al-Khwarizmi's name. Al-Khwarizmi was the most widely read mathematician in Europe in the late Middle Ages, primarily through his other book, the Algebra. In late medieval Latin, algorismus, English 'algorism', the corruption of his name, simply meant the "decimal number system". In the 15th century, under the influence of the Greek word ἀριθμός 'number' (cf. 'arithmetic'), the Latin word was altered to algorithmus, and the corresponding English term 'algorithm' is first attested in the 17th century; the modern sense was introduced in the 19th century.
Cartesian. Fuchsian. Boolean. Pfaffian. Hermitian.
Wrong part of speech, but I'm fond of Bezoutiant. [Maybe Bezoutian is more elegant, but the form I'm fond of has the T at the end.]
Alas, these all have capital letters. One might think a schlicht function was eponymous (there are mathematicians called Schlicht) but not so.
This is off topic, but back in the day, while dumpster diving for profs' discarded offprints, I found an offprint for a paper with a title like "On the Poynting Vector of Cosmic Love Waves". I think Haight-Ashbery was just becoming a thing then, and the title tickled my fancy.
Changing the topic to eponymous monstrosities, we have Rao-Blackwellization. (A swell concept, which might otherwise be called Jensenification, if I had any say in the matter.)
Changing topix yet again. I have just learned that there are entries for people with these surnames in the Math Genealogy database: Eigen, Star, Strong, Stronger, and Null. So they are like Schlict: non eponyms of strong topoogy, stronger topology, and null set.
Platonic solids, though usually capitalized.
Studentized residuals, Studentized ranges.
archimedean (e.g., archimedean valuation or nonarchimedean valuation) -- some people capitalize and some don't (also some people hyphenate nonarchimedean and some don't). i never capitalize or hyphenate.