Spectral sequences of algebras in SageMath
John Palmieri (University of Washington)
SageMath includes an implementation of commutative differential graded algebras over a field. The proposed project will build on this to set up a framework for computations of spectral sequences of algebras. This will start with brainstorming --- what do we want such a framework to entail, what can we hope to compute, what should the interface be, what sort of input and outputs might we want? Prerequisites: for the brainstorming, a little familiarity with SageMath wouldn't hurt but is not necessary. For implementing the ideas, you need to know Python.
Equivariant algebra and Cp Mackey Functors
Ben Spitz (Indiana University Bloomington)
The CpMackeyFunctors package for Macaulay2 was recently developed by the two project leaders, together with Chan, Mudrak, Vogeli, Wang, Zeng, and Zotine. It provides computational support for working with the abelian category of Mackey functors over a cyclic group of prime order, including random constructors and the ability to compute resolutions, ext and tor. In this project, we will expand the functionality of this package to include Green functors and modules over them, equivariant ideals, and other constructions over Cp. This project is suitable for coders of all levels and anyone interested in working with computational equivariant algebra.
Mackey functors in OSCAR
Thomas Brazelton (Harvard University)
Working closely with the Cp Mackey functors project, we will port and expand existing computational methods for Mackey functors into the OSCAR framework in Julia. Using the GAP interface, we will define data types which allow us to work with G-Mackey functors for arbitrary finite groups G. This project is suitable for more advanced coders, or those who have experience in Julia.
Machine computation of the equivariant slice spectral sequence
Danny Shi (University of Washington)
This working group will focus on developing tools and methods for machine-assisted computations for the equivariant slice spectral sequence. The goal is to translate the input data of equivariant stable homotopy theory, including representation gradings, Mackey functors, slice cells, differentials, and extension problems, into forms that can be systematically computed and checked by computer. We will discuss both the mathematical structure underlying these computations and the design of algorithms that can make large-scale slice spectral sequence calculations possible. Examples will be drawn from familiar equivariant spectra such as norms of Real bordism theories and Lubin–Tate theories.
The R-motivic Adams spectral sequence
Eva Belmont (Case Western Reserve University)
The R-motivic Adams spectral sequence converges to the (2-complete) R-motivic homotopy groups of the sphere. The goal is to compute the Adams E2 page in a range using the rho-Bockstein spectral sequence. The E1-page of the rho-Bockstein spectral sequence has been computed in a large range in C-motivic terms. Prior work of Isaksen and myself suggests that the rho-Bockstein spectral sequence is highly constrained: while there isn't exactly an algorithm for determining the differentials, in practice one can determine differentials by using known structure (such as multiplications) along with comparison with the rho-localization, which says that almost all classes must participate in a differential.
The project involves turning the techniques that Isaksen and I used into a constraint satisfaction problem which can then be fed into a SAT solver (an off-the-shelf tool for solving boolean constraint satisfaction problems). A stretch goal or extension project is to do the same for the C2-equivariant rho-Bockstein spectral sequence as described by Guillou and Isaksen, which computes the E2 page of the C2-equivariant Adams spectral sequence.
The code will be written in python. Some familiarity with python will be expected, but a little focused self-study before the workshop should suffice.
Higher (dual) Steenrod algebras
Achim Krause (University of Oslo)
From the adjunction between spectra and the derived category of F_p, one gets a corresponding comonad on D(F_p). Its coalgebras can be regarded as a coherent form of comodules over the dual Steenrod algebra. While we want to eventually make this type of structure fully amenable to computer calculations, in this project we want to focus on developing software to work with its 2-categorical truncation. The resulting theory is equivalent to Baues' secondary Steenrod algebra (and its modules), serving as an important testing ground for generalizing to higher categorical level.
Programming prerequisites: Python
Mathematical prerequisites: some familiarity with higher category theory, stable homotopy theory and Steenrod operations would be ideal
Python bindings for sseq
Hood Chatham (Cloudflare)
sseq is a software library written in Rust to compute minimal resolutions of
chain complexes over the Steenrod Algebra. It is designed to attain a compromise
between ease of use, generality, and performance.
However, Rust is not all that convenient of a language for math experimentation.
Python would be easier for most users. The goal of this project is to create
Python bindings that are sufficiently expressive to translate the Rust code
examples to Python. Alternatively, bring your favorite use case and translate
that to Python.
I am also happy to provide tutorials in the use of the core Ext libraries or to
supervise the addition of a feature.