Search arXiv⌕ Search

arXiv · 2009.12160

Higher-order contact mechanics

Abstract

We present a complete theory of higher-order autonomous contact mechanics, which allows us to describe higher-order dynamical systems with dissipation. The essential tools for the theory are the extended higher-order tangent bundles, ${\rm T}^kQ\times{\mathbb R}$, whose geometric structures are previously introduced in order to state the Lagrangian and Hamiltonian formalisms for these kinds of systems, including their variational formulation. The variational principle, the contact forms, and the geometric dynamical equations are obtained by using those structures and generalizing the standard formulation of contact Lagrangian and Hamiltonian systems. As an alternative approach, we develop a unified description that encompasses the Lagrangian and Hamiltonian equations as well as their relationship through the Legendre map; all of them are obtained from the contact dynamical equations and the constraint algorithm that is implemented because, in this formalism, the dynamical systems are always singular. Some interesting examples are finally analyzed using these geometric formulations.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Manuel de León, Jordi Gaset, Manuel Laínz, Miguel C. Muñoz-Lecanda, Narciso Román-Roy. 2021-02-01. Higher-order contact mechanics. https://doi.org/10.1016/j.aop.2021.168396

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Field Theory via Higher Geometry II: Thickened Smooth Sets as Synthetic Foundations

This is the second in a series of papers that aim to develop rigorous and most encompassing foundations for field theory, where in the first installment we laid out the natural formulation of bosonic variational field theory via the ``functorial geometry'' of smooth sets, namely in the topos over the site of spaces with smooth maps between them. Here, we extend this to the category ThickenedSmoothSets of {\it infinitesimally thickened smooth sets}. We first describe the Cahiers topos in a simplified, but still fully rigorous, $\mathbb{R}$-algebraic setting -- which should serve as a more accessible introduction to the theory of Synthetic Differential Geometry to both physicists and mathematicians. Then, we formulate local Lagrangian field theory in this setting in which infinitesimal spaces exist and interact correctly with the field-theoretic spaces of infinite jet bundles, off-shell and on-shell spaces of fields etc. This discussion subsumes previous constructions and further recovers all the relevant tangent bundles of traditional (off-shell and on-shell) field theory considerations via the synthetic tangent bundle construction, i.e., as ``infinitesimal curves'' in those spaces, which were previously defined only in an indirect manner. Beyond finally putting such aspects of the theory on a firm foundation, this approach recognizes the variational principle of local Lagrangian field theory, equivalently, as an intersection of thickened smooth sets. Lastly, as we will show in detail, it permits a mathematical formalization (and recovery) of perturbative field theory as the actual restriction to the infinitesimal neighborhood around a field configuration -- a statement which thus far had remained only in the realm of intuition. Crucially, all of these results are obtained with no use of infinite dimensional manifold theory, topology or functional analysis of mapping spaces.

math-ph↗

Gradual eigenvector ergodization in coupled Ginibre matrices

Non-Hermitian random matrices provide a useful framework for understanding universal characteristics of dissipative quantum chaotic systems with loss or gain. We consider a model of two such systems represented by two independent $N\times N$ complex Ginibre matrices interacting via a deterministic matrix $c{\bf 1}_N$, where $c$ is the complex coupling parameter whose magnitude $|c|$ controls the interaction strength. We characterize quantitatively how the eigenvectors of the whole system, initially localized in one of the individual subsystems for $|c|=0$, eventually spread over the full system with growing interaction strength. The resulting asymptotic formula describing such spread in the limit $N\to \infty$ is very explicit and provides a full picture of the gradual ergodization of eigenvectors as a function of the coupling parameter $|c|$ in the whole transition regime. As a by-product of our method we also compute the mean eigenvalue density for our model at the origin of the spectral bulk $z=0$ in the fully ergodic regime, when the coupling is scaled with the matrix size as $c=\sqrt{N}\tilde{c}$. We find that as $N\to \infty$ the limiting density at the origin vanishes beyond the critical value $|\tilde{c}|=1.$ This is compatible with the expected split of the density support in the complex plane into two disjoint domains.

math-ph↗

Structure-preserving diffuse-domain accelerated saddle dynamics for wetting transitions

Wetting transitions on textured substrates play a central role in the design of functional surfaces, but resolving their transition mechanisms requires efficient exploration of complex energy landscapes. In particular, saddle points are essential for revealing the connectivity among metastable states and transition pathways. In this work, we develop a diffuse-domain accelerated saddle dynamics (DD-ASD) framework for mass-constrained wetting transitions on complex textured substrates. The diffuse-domain formulation embeds complex solid geometries into a Cartesian grid, avoiding body-fitted mesh construction in repeated saddle-point searches. An orthogonal projection is applied consistently to the phase-field state and unstable-direction dynamics, preserving the prescribed droplet mass at the discrete level. Momentum acceleration is incorporated into the saddle dynamics to improve the efficiency of high-index saddle searches. Under the stated local spectral and exact-eigenspace assumptions, we establish a local convergence rate of $1-\mathcal{O}(1/\sqrtκ)$ on the effective mass-conserving subspace. Numerical experiments demonstrate the effectiveness of the proposed method in resolving wetting solution landscapes, transition pathways, and energy barriers on textured substrates. We further extend the framework to fully three-dimensional wetting-landscape computations.

math-ph↗