Existence of the random-to-random shuffle limit profile

Determine whether the total variation limit profile exists for the random-to-random card shuffle at its cutoff time and window.

Background

The random-to-random card shuffle selects a card uniformly, removes it, and reinserts it at a uniformly chosen position. The paper states that this shuffle has cutoff with a specified cutoff location and window, and that its transition matrix has been spectrally analyzed.

The continuity theorem applies conditionally: if the limit profile exists, then the available spectral estimates imply continuity for the relevant range of the profile parameter. The existence of the limit profile itself is left unresolved.

References

The limit profile of random--to--random (if it exists) is not known.

Continuity for Limit Profiles of Reversible Markov Chains  (2503.09550 - Nestoridi, 12 Mar 2025) in Section 5, subsection “Random--to--random”