17 citations · 74 across the 14 of their papers we have counts for
14 papers
Exponential decay in -invariant quantum spin systems
Jakob E. Björnberg, Kieran Ryan
We consider -invariant and reflection-positive quantum spin systems on the integer lattice in any dimension, and prove that spin-spin correlations decay exponentially fast pr…
The scaling limit of random 2-connected series-parallel maps
Daniel Amankwah, Jakob Björnberg, Sigurdur Örn Stefánsson +2
A finite graph embedded in the plane is called a series-parallel map if it can be obtained from a finite tree by repeatedly subdividing and doubling edges. We study the scaling lim…
Reflection positivity and infrared bounds for quantum spin systems
Jakob E. Björnberg, Daniel Ueltschi
The method of reflection positivity and infrared bounds allows to prove the occurrence of phase transitions in systems with continuous symmetries. We review the method in the conte…
Heisenberg models and Schur--Weyl duality
Jakob Björnberg, Hjalmar Rosengren, Kieran Ryan
We present a detailed analysis of certain quantum spin systems with inhomogeneous (non-random) mean-field interactions. Examples include, but are not limited to, the interchange- a…
Correlation inequalities for the uniform 8-vertex model and the toric code model
Jakob E. Björnberg, Benjamin Lees
We elucidate connections between four models in statistical physics and probability theory: (1) the toric code model of Kitaev, (2) the uniform eight-vertex model, (3) random walk…
Characterising random partitions by random colouring
Jakob E. Björnberg, Cécile Mailler, Peter Mörters +1
Let be a random partition of the unit interval , i.e. and , and let be i.i.d. Bernoulli r…