On the problem of stability for higher-order derivative Lagrangian systemsLetters in Mathematical Physics - Tập 14 - Trang 311-319 - 1987
Enrico Pagani, Giampietro Tecchiolli, Sergio Zerbini
The problem of stability for dynamical systems whose Lagrangian function depends
on the derivatives of a higher order than one is studied. The difficulty of this
analysis arises from the indefiniteness of the Hamiltonian, so that the
well-known Lagrange-Dirichlet theorem cannot be used and the methods of the
canonical perturbation theory (KAM theory) must be employed. We show, with an
example, tha... hiện toàn bộ
Pseudodifferential Operators of Several Variables and Baker FunctionsLetters in Mathematical Physics - Tập 60 - Trang 1-8 - 2002
Min Ho Lee
The KP hierarchy consists of an infinite system of nonlinear partial
differential equations and is determined by Lax equations, which can be
constructed using pseudodifferential operators. The KP hierarchy and the
associated Lax equations can be generalized by using pseudodifferential
operators of several variables. We construct Baker functions associated to those
generalized Lax equations of seve... hiện toàn bộ
Three-dimensional model of relativistic-invariant field theory, integrable by the Inverse Scattering TransformLetters in Mathematical Physics - Tập 5 - Trang 247-253 - 1981
S. V. Manakov, V. E. Zakharov
In the space-time with signature (2,2) the self-duality equations in the
specific case of potentials independent of one of the coordinates are reduced to
a relativistic-invariant system in the (2-1)-dimensional space-time. A general
solution of this system is constructed by means of IST. A soliton solution,
finite in all directions, is discussed. It is found that there is no classical
scattering o... hiện toàn bộ
Removing Metric Anomalies from Ray–Singer TorsionLetters in Mathematical Physics - Tập 47 - Trang 149-158 - 1999
D. Burghelea
Ray–Singer torsion is a numerical invariant associated with a compact Riemannian
manifold equipped with a flat bundle and a Hermitian structure on this bundle.
In this Letter, we show how one can remove the dependence on the Riemannian
metric and on the Hermitian structure with the help of a base point and of a
Euler structure in order to obtain a topological invariant. A numerical
invariant for a... hiện toàn bộ
Examples of Twisted Cyclic Cocycles from Covariant Differential CalculiLetters in Mathematical Physics - Tập 64 - Trang 245-254 - 2003
Konrad Schmüdgen, Elmar Wagner
For two covariant differential *-calculi, the twisted cyclic cocycle associated
with the volume form is represented in terms of commutators $$\left[
{\mathcal{F},\rho \left( x \right)} \right]$$ for some self-adjoint operator
$$\mathcal{F}$$ and some *-representation ρ of the underlying *-algebra.... hiện toàn bộ
The existence of Solitons in Gauged Sigma Models with Broken Symmetry: Some RemarksLetters in Mathematical Physics - Tập 40 - Trang 177-189 - 1997
Yisong Yang
We prove the existence of multisolitons in the gauged self-dual Maxwell and
Chern–Simons sigma models with broken symmetry. In the context of topological
solutions, the existence proofs rely on established results on earlier models.
In the context of nontopological solutions with radial symmetry, the proof is by
adapting a shooting argument.
On Root Multiplicities of Some Hyperbolic Kac–Moody AlgebrasLetters in Mathematical Physics - Tập 42 - Trang 153-166 - 1997
Michel Bauer-Violette, Denis Bernard
Using the coset construction, we compute the root multiplicities at level-3 for
some hyperbolic Kac–Moody algebras including the basic hyperbolic extension of
A1 1 and E10.