Related papers: Compact Q-balls and Q-shells in a scalar electrody…
We consider Friedberg-Lee-Sirlin Q-balls in a (3+1)-dimensional model with vanishing scalar potential of one of the fields. The Q-ball is stabilized by the gradient energy of this field and carries scalar charge, over and beyond the global…
We study Q-balls associated with local U(1) symmetries. Such Q-balls are expected to become unstable for large values of their charge because of the repulsion mediated by the gauge force. We consider the possibility that the repulsion is…
Rotational excitations of compact Q-balls in the complex signum-Gordon model in 2+1 dimensions are investigated. We find that almost all such spinning Q-balls have the form of a ring of strictly finite width. In the limit of large angular…
This paper is concerned with the dynamics and interactions of Q-balls in (1+1)-dimensions. The asymptotic force between well-separated Q-balls is calculated to show that Q-balls can be attractive or repulsive depending upon their relative…
Non topological solitons, Q-balls can arise in many particle theories with U(1) global symmetries. As was shown by Cohen et al. \cite{Qballscohen}, if the corresponding scalar field couples to massless fermions, large Q-balls are unstable…
We present compact Q-balls in an (Anti-)de Sitter background in D dimensions, obtained with a V-shaped potential of the scalar field. Beyond critical values of the cosmological constant compact Q-shells arise. By including the gravitational…
Cold atoms bring new opportunities to study quantum magnetism, and in particular, to simulate quantum magnets with symmetry greater than $SU(2)$. Here we explore the topological excitations which arise in a model of cold atoms on the…
We study angularly excited as well as interacting non-topological solitons, so-called Q-balls and their gravitating counterparts, so-called boson stars in 3+1 dimensions. Q-balls and boson stars carry a non-vanishing Noether charge and…
Bosons carrying a conserved charge can form stable bound states if their Lagrangian contains attractive self-interactions. Bound-state configurations with a large charge $Q$ can be described classically and are denoted as Q-balls, their…
We study the evolution of Q-balls under a spontaneously broken global $U(1)$ symmetry. Q-balls are stabilized by the conservation of $U(1)$ charge, but when the symmetry is spontaneously broken, the resulting Nambu-Goldstone (NG) boson can…
The physical properties of bound-state charged massive scalar field configurations linearly coupled to a spherically symmetric charged reflecting shell are studied {\it analytically}. To that end, we solve the Klein-Gordon wave equation for…
Q-balls are non-topological solitonic solutions to a wide class of field theories that possess global symmetries. Here we show that in these same theories there also exists a tower of novel composite Q-ball solutions where, within one…
It is shown that an alternative to the standard scalar QED is possible. In this new version there is only global gauge invariance as far as the charged scalar fields are concerned although local gauge invariance is kept for the…
In the present work we investigate the existence and stability properties of q-balls which consist of a couple of scalar fields, forming an SU(2) doublet in a Lagrangian with a global SU(2) symmetry. We find that these spinors can form a…
A new kind of Q-balls is found: Q-balls in a non-linear sigma model. Their main properties are presented together with those of their self-gravitating generalization, sigma model Q-stars. A simple special limit of solutions which are bound…
While $CP^N$ models with analytic potentials are known to support finite-energy compact Q-ball and Q-shell solutions, their behavior in more complex Lagrangian frameworks remains a subject of active research. This work explores these…
We investigate the properties of interacting Q-balls and boson stars that sit on top of each other in great detail. The model that describes these solutions is essentially a (gravitating) two-scalar field model where both scalar fields are…
This work deals with charged nontopological solutions that appear in relativistic models described by a single complex scalar field in two-dimensional spacetime. We study a model which supports novel analytical configurations of the Q-ball…
We show that many numerically established properties of Q-balls can be understood in terms of analytic approximations for a certain type of potential. In particular, we derive an explicit formula between the energy and the charge of the…
We investigate the presence of non-topological solutions of the Q-ball type in (1, 1) spacetime dimensions. The model engenders the global U(1) symmetry and is of the k-field type, since it contains a new term, of the fourth-order power in…