Herzog–Schönheim conjecture for solvable groups
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The Herzog–Schönheim question for solvable groups asks whether any exact partition of a finite or infinite solvable group into at least two left cosets must use two subgroups with the same index.
Why it matters and what counts as progress
Why it matters: It asks whether solvability alone forces repeated subgroup indices in every exact coset partition, even for infinite groups.
What counts as progress: Prove the repeated-index conclusion for all solvable groups, including infinite groups, or produce an exact coset partition with pairwise distinct indices.
How the problem developed
- 1974 · Conjecture [1]
M. Herzog and J. Schönheim Proposed that every finite coset partition of a group contains two cosets whose subgroups have equal index.
- September 1986 · Special case [2]
Marc A. Berger, Alexander Felzenbaum and Aviezri Fraenkel Proved the conjecture for finite nilpotent groups, a solvable-group subclass.
- 30 Sept 2025 · Special case [3]
Martino Garonzi and Leo Margolis Reported proofs for finite simple and symmetric groups; these families do not cover all solvable groups.
- 2 Oct 2026 · Solvable group result [4]
Murali Menon Registered a Lean-verified index-form proof for every solvable group, finite or infinite; the arbitrary-group conjecture remains open.
AI contribution
AI-developed proof of the Herzog–Schönheim conjecture for solvable groups
In an exact partition of any finite or infinite solvable group into at least two left cosets, two of the corresponding subgroups have the same index. The cardinality form of Erdős Problem 274 follows.
Sources
- Jonoska, Savchuk and Chouraqui, An Approach to the Herzog-Schönheim Conjecture Using Automata
- Berger, Felzenbaum and Fraenkel, The Herzog-Schönheim Conjecture for Finite Nilpotent Groups
- Martino Garonzi and Leo Margolis, The Herzog-Schönheim conjecture for simple and symmetric groups
- Murali Menon, The Herzog–Schönheim conjecture for solvable groups — Palomar registry
- Menon’s solvable-group formalization
- Erdős Problem 274 formal statement
Website timeline
Publication dates and editorial changes.
AI-developed proof of the Herzog–Schönheim conjecture for solvable groups