Quench Dynamics in Two-Dimensional Integrable SUSY Models

We analyse quench processes in two dimensional quantum field theories with infinite number of conservation laws which also include fermionic charges that close a N=1 supersymmetric algebra. While in general the quench protocol induces a breaking of supersymmetry, we show that there are particular initial states which ensure the persistence of supersymmetry also for the dynamics out of equilibrium. We discuss the conditions that identify such states and, as application, we present the significant cases of the Tricritical Ising Model and the Sine-Gordon model at its supersymmetric point. We also address the issue of the Generalized Gibbs Ensemble in the presence of fermionic conserved charges

R\ue9nyi entropies of generic thermodynamic macrostates in integrable systems

We study the behaviour of R\ue9nyi entropies in a generic thermodynamic macrostate of an integrable model. In the standard quench action approach to quench dynamics, the R\ue9nyi entropies may be derived from the overlaps of the initial state with Bethe eigenstates. These overlaps fix the driving term in the thermodynamic Bethe ansatz (TBA) formalism. We show that this driving term can be also reconstructed starting from the macrostate's particle densities. We then compute explicitly the stationary R\ue9nyi entropies after the quench from the dimer and the tilted N\ue9el state in XXZ spin chains. For the former state we employ the overlap TBA approach, while for the latter we reconstruct the driving terms from the macrostate. We discuss in full detail the limits that can be analytically handled and we use numerical simulations to check our results against the large time limit of the entanglement entropies

Estimating Neonatal Oxygen Consumption from Heart Rate

ABSTRACT The relationship between heart rate (HR) and oxygen consumption (V̇o2) has been investigated in a sample of 20 low‐risk, term neonates aged 14–48 hrs. Repeated, simultaneous measurements of HR and V̇o2 were performed on each neonate during each of three epochs ordered by increasing level of activity. A robust linear relationship was found between HR and V̇o2, with an average correlation of.90. Substantial variation was observed across individuals in the slope of the HR‐V̇o2 regression line. This variation was curvilinearly related to ponderal index (PI), with low PI neonates having the shallowest and steepest slopes. These findings suggest that HR may provide a flexible, non‐restrictive means of estimating neonatal V̇o2 but that the impact of prenatal growth history and postnatal growth performance on the estimation of V̇o2 from HR merits further investigation