In the last decade, there has been an increasing interest in the analysis of energy level
spectra and wave functions of nuclei, particles, atoms and other quantum many-body …

Quantum chaos is generally referred to as the study of quantum manifestations or
fingerprints of nonlinear dynamical and chaotic behaviors in the corresponding classical …

The concentrations of wave functions about classical periodic orbits, or quantum scars, are a
fundamental phenomenon in physics. An open question is whether scarring can occur in …

Scar theory is one of the fundamental pillars in the field of quantum chaos, and scarred
functions are a superb tool to carry out studies in it. Several methods, usually semiclassical …

This paper deals with the computation of periodic orbits of dynamical systems up to any
arbitrary precision. These very high requirements are useful, for example, in the studies of …

Excited-state quantum phase transitions (ESQPTs) are critical phenomena that generate
singularities in the spectrum of quantum systems. For systems with a classical counterpart …

We present an approach to calculating the quantum resonances and resonance wave
functions of chaotic scattering systems, based on the construction of states localized on …

In addition to the well-known scarring effect of periodic orbits, we show here that homoclinic
and heteroclinic orbits, which are cornerstones in the theory of classical chaos, also scar …

Quantum manifestations of the dynamics around resonant tori in perturbed Hamiltonian
systems, dictated by the Poincaré-Birkhoff theorem, are shown to exist. They are embedded …

Unexpected formation of regular high-Q whispering gallery modes in a deformed microdisk
where the radius is of the order of the vacuum wavelength is explained in terms of partial …