Excitable media support circulating waves on a one-dimensional ring. Continuity arguments, developed originally for resetting limit cycle oscillations in finite-dimensional dynamical systems, suggest that there must exist a range of phases and amplitudes for perturbations of the reentrant wave that lead to its annihilation. The annihilation is illustrated in the Fitzhugh-Nagumo equation of exci...

The hyperoctahedral group acting on R is the Weyl group of type B and is associated with a two-parameter family of differential-difference operators {Ti : 1 ≤ i ≤ N}. These operators are analogous to partial derivative operators. This paper finds all the polynomials h on R which are harmonic, ∆Bh = 0 and annihilated by Ti for i > 2, where the Laplacian ∆B = ∑ N i=1 T 2 i . They are given explic...

It is shown that electron-positron pair production is expected to occur in post-disruption plasmas in large tokamaks, including JET and JT-60U, where up to about 10(14) positrons may be created in collisions between multi-MeV runaway electrons and thermal particles. If the loop voltage is large enough, they are accelerated and form a beam of long-lived runaway positrons in the direction opposit...

We consider some aspects of counting BPS operators which are annihilated by two supercharges, in superconformal field theories. For non-zero coupling, the corresponding multi-variable partition functions can be written in terms of generating functions for vector partitions or their weighted generalisations. We derive asymptotics for the density of states for a wide class of such multi-variable ...

A jump process for the positions of interacting quantum particles on a lattice, with time-dependent transition rates governed by the state vector, was first considered by J.S. Bell. We review this process and its continuum variants involving “minimal” jump rates, describing particles as they get created, move, and get annihilated. In particular, we sketch a recent proof of global existence of B...

This article investigates two contemporary Italian novels treating femicide: Undicesimo comandamento (2011) by Elena Mearini and Padreterno (2015) Caterina Serra. It draws on feminist insights that consider practices of revising retrieving mythology as an opportunity to launch a process re-symbolisation, one capable challenging patriarchal discrimination violence. In particular, the examines Me...

Archaeologists have traditionally framed the impacts of natural disasters in terms societal collapse versus cultural resilience. The 7.3ka cal BP Kikai-Akahoya (K-Ah) ‘super-eruption’ south-western Japan was among largest volcanic events Holocene. Here, authors deploy a multi-proxy approach to examine how K-Ah devastated Tanegashima Island. While local Jōmon populations were annihilated, surrou...

Starting from the expression for the superdeterminant of (xI −M), where M is an arbitrary supermatrix , we propose a definition for the corresponding characteristic polynomial and we prove that each supermatrix satisfies its characteristic equation. Depending upon the factorization properties of the basic polynomials whose ratio defines the above mentioned superdeterminant we are able to constr...

Decoherence in quantum computers is formulated within the semigroup approach. The error generators are identified with the generators of a Lie algebra. This allows for a comprehensive description which includes as a special case the frequently assumed spin-boson model. A generic condition is presented for errorless quantum computation: decoherence-free subspaces are spanned by those states whic...