K. Ryan

collaborators

2 papers

math-ph2025

Exponential decay in $O (n)$ -invariant quantum spin systems

Jakob E. BjÃ¶rnberg, Kieran Ryan

We consider $O (n)$ -invariant and reflection-positive quantum spin systems on the integer lattice in any dimension, and prove that spin-spin correlations decay exponentially fast pr…

math-ph2025

Dimerization in $O (n)$ -invariant quantum spin chains

J. E. BjÃ¶rnberg, J. E. Björnberg, K. Ryan

We establish dimerization in $O (n)$ -invariant quantum spin chains with large enough $n$ , in a much larger region of the phase diagram than previous results. This entails identifyin…

Exponential decay in O(n)-invariant quantum spin systems

Dimerization in O(n)-invariant quantum spin chains

Exponential decay in $O (n)$ -invariant quantum spin systems

Dimerization in $O (n)$ -invariant quantum spin chains