I think the statement is that the functor 𝕎: CRing → CRing is given by Spec of the ring of symmetric functions
November 9, 2025 at 9:07 PM
I think the statement is that the functor 𝕎: CRing → CRing is given by Spec of the ring of symmetric functions
2/ I would like to understand genuine ∑_n-equivariant homotopy theory, in particular this paper arxiv.org/abs/1801.01491. At one point I aspired to compute the ∑_n-slice filtration of ∑^∞ |∏_n| using their paper. However, that project is too ambitious/time-consuming now that I've left math.
The Action of Young Subgroups on the Partition Complex
We study the restrictions, the strict fixed points, and the strict quotients of the partition complex $|Π_n|$, which is the $Σ_n$-space attached to the poset of proper nontrivial partitions of the set...
arxiv.org
November 8, 2025 at 1:08 AM
2/ I would like to understand genuine ∑_n-equivariant homotopy theory, in particular this paper arxiv.org/abs/1801.01491. At one point I aspired to compute the ∑_n-slice filtration of ∑^∞ |∏_n| using their paper. However, that project is too ambitious/time-consuming now that I've left math.
I wish I knew more about them for a few reasons:
1) I frequently need to manipulate identities in 𝛌-rings, and Young tableaux give a conceptual explanation of the change-of-basis formulas between the different families of operations (in the p-typical context I need both δ_n and θ_n)
1) I frequently need to manipulate identities in 𝛌-rings, and Young tableaux give a conceptual explanation of the change-of-basis formulas between the different families of operations (in the p-typical context I need both δ_n and θ_n)
November 8, 2025 at 1:04 AM
I wish I knew more about them for a few reasons:
1) I frequently need to manipulate identities in 𝛌-rings, and Young tableaux give a conceptual explanation of the change-of-basis formulas between the different families of operations (in the p-typical context I need both δ_n and θ_n)
1) I frequently need to manipulate identities in 𝛌-rings, and Young tableaux give a conceptual explanation of the change-of-basis formulas between the different families of operations (in the p-typical context I need both δ_n and θ_n)
you are there now, go dance in the street
November 5, 2025 at 5:04 AM
you are there now, go dance in the street
There's a compelling argument (Hesselholt-Pstragowski's Dirac geometry, the even filtration) for indexing homotopy groups by half-integers, so that π₂ becomes π₁ and π₁ becomes π_{1/2}.
October 5, 2025 at 6:27 PM
There's a compelling argument (Hesselholt-Pstragowski's Dirac geometry, the even filtration) for indexing homotopy groups by half-integers, so that π₂ becomes π₁ and π₁ becomes π_{1/2}.
This is one of the first things in @jeremykun.com's "A Programmer's Introduction to Mathematics", and one of the reasons I recommend it to people. Reading a formula gives you the general gist, writing it out yourself forces you to think about each individual term.
August 10, 2025 at 6:56 AM
This is one of the first things in @jeremykun.com's "A Programmer's Introduction to Mathematics", and one of the reasons I recommend it to people. Reading a formula gives you the general gist, writing it out yourself forces you to think about each individual term.
later in the same paper
June 25, 2025 at 5:23 PM
later in the same paper