We investigate the scattering of elastic waves off a disordered region described by one-dimensional random-phase sine-Gordon model. The collective pinning results in an effective static disorder potential with universal and non-Gaussian correlations, acting on propagating waves. find signatures correlations wave transmission wide frequency range, which covers both weak strong localization regim...

Discrete breathers are found in a nonlinear one dimensional axially loaded mechanical lattice consisting of rigid links supported laterally by linear springs. We find link centered breathers for an odd number of mechanical links and pivot centred breathers where the number of links is even. Substantial parameter regions in load–frequency parameter space are found where these breathers are linea...

The pinning of flux lattices by weak impurity disorder is studied in the absence of free dislocations using both the gaussian variational method and, to O(ǫ = 4 − d), the functional renormalization group. We find universal logarithmic growth of displacements for 2 < d < 4: 〈u(x) − u(0)〉2 ∼ Ad log |x| and persistence of algebraic quasi-long range translational order. When the two methods can be ...

We introduce a system with one or two amplified nonlinear sites ('hot spots', HSs) embedded into a two-dimensional linear lossy lattice. The system describes an array of evanescently coupled optical or plasmonic waveguides, with gain applied to selected HS cores. The subject of the analysis is discrete solitons pinned to the HSs. The shape of the localized modes is found in quasi-analytical and...

We present a model of a freely precessing neutron star which is then compared against pulsar observations. The aim is to draw conclusions regarding the structure of the star, and test theoretical ideas of crust-core coupling and superfluidity. We argue that, on theoretical grounds, it is likely that the core neutron superfluid does not participate in the free precession of the crust. We apply o...