435 research outputs found
Study of Stability of a Charged Topological Soliton in the System of Two Interacting Scalar Fields
An analytical-numerical analysis of the singular self-adjoint spectral
problem for a system of three linear ordinary second-order differential
equations defined on the entire real exis is presented. This problem comes to
existence in the nonlinear field theory. The dependence of the differential
equations on the spectral parameter is nonlinear, which results in a quadratic
operator Hermitian pencil.Comment: 22 pages, 2 figure
Radial excitations of Q-balls, and their D-term
We study the structure of the energy-momentum tensor of radial excitations of
Q-balls in scalar field theories with U(1) symmetry. The obtained numerical
results for the excitations allow us to study in detail
patterns how the solutions behave with N. We show that although the fields and
energy-momentum tensor densities exhibit a remarkable degree of complexity, the
properties of the solutions scale with N with great regularity. This is to best
of our knowledge the first study of the D-term d1 for excited states, and we
demonstrate that it is negative --- in agreement with results from literature
on the d1 of ground state particles.Comment: 11 pages, 12 figure
Stable branches of a solution for a fermion on domain wall
We discuss the case when a fermion occupies an excited non-zero frequency
level in the field of domain wall. We demonstrate that a solution exists for
the coupling constant in the limited interval . We
show that indeed there are different branches of stable solution for in
this interval. The first one corresponds to a fermion located on the domain
wall (). The second branch, which belongs to the interval
, describes a polarized fermion off the domain
wall. The third branch with describes an excited antifermion in
the field of the domain wall.Comment: 15 pages, 7 figures, references adde
A remark on collisions of domain walls in a supersymmetric model
The process of collision of two parallel domain walls in a supersymmetric
model is studied both in effective Lagrangian approximation and by numerical
solving of the exact classical field problem. For small initial velocities we
find that the walls interaction looks like elastic reflection with some delay.
It is also shown that in such approximation internal parameter of the wall may
be considered as a time-dependent dynamical variable.Comment: 6 pages, LaTeX, 3 figures (eps), fig. 2 correcte
Multi-kink collisions in the model
We study simultaneous collisions of two, three, and four kinks and antikinks
of the model at the same spatial point. Unlike the kinks, the
kinks are asymmetric and this enriches the variety of the collision
scenarios. In our numerical simulations we observe both reflection and bound
state formation depending on the number of kinks and on their spatial ordering
in the initial configuration. We also analyze the extreme values of the energy
densities and the field gradient observed during the collisions. Our results
suggest that very high energy densities can be produced in multi-kink
collisions in a controllable manner. Appearance of high energy density spots in
multi-kink collisions can be important in various physical applications of the
Klein-Gordon model.Comment: 21 pages, 8 figures; v2: minor changes to match version published in
JHE
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