Robert Griffiths Hodgins (1920–2010)

Temporal Griffiths phases.

Disorder is an unavoidable ingredient of real systems. Spatial disorder generates Griffiths phases (GPs) which, in analogy to critical points, are characterized by a slow relaxation of the order parameter and divergences of quantities such as the susceptibility. However, these singularities appear in an extended region of the parameter space and not just at a (critical) point, i.e., there is ge...

Griffiths, Elimination & Psychopathology

Lemuel Matthews Griffiths

The Bristol Medico-Chirurgical Society mourns the loss of Lemuel Matthews Griffiths, who died on September 22nd, lri eightieth year, an Ex-President and one of its earliest an(i most active members. With this issue already in the Press it is quite impossible to do justice to his memory or give a(lequate expression to the well-earned gratitude of his medical c?nfreres in Bristol for the many yea...

Griffiths phases on complex networks.

Quenched disorder is known to play a relevant role in dynamical processes and phase transitions. Its effects on the dynamics of complex networks have hardly been studied. Aimed at filling this gap, we analyze the contact process, i.e., the simplest propagation model, with quenched disorder on complex networks. We find Griffiths phases and other rare-region effects, leading rather generically to...

Critical behavior of Griffiths ferromagnets.

From a heuristic calculation of the leading order essential singularity in the distribution of Yang-Lee zeroes, we obtain new scaling relations near the ferromagnetic-Griffiths transition, including the prediction of a discontinuity on the analogue of the critical isotherm. We show that experimental data for the magnetization and heat capacity of La(0.7)Ca(0.3)MnO(3) are consistent with these p...