Let $\mathrm{\Sigma }$ be a constrained mechanical system locally referred to state coordinates $(q^1,\mathrm{\dots },q^N,{\gamma }^1,\mathrm{\dots },{\gamma }^M)$. Let $({\tilde{\gamma }}^1\mathrm{\dots }{\tilde{\gamma }}^M)(\cdot )$ be an assigned trajectory for the coordinates ${\gamma }^{\alpha }$ and let $u(\cdot )$ be a scalar function of the time, to be thought as a control. In [4] one considers the control system ${\mathrm{\Sigma }}_{\widehat{\gamma }}$, which is parametrized by the coordinates $(q^1,\mathrm{\dots },q^N)$ and is obtained from $\mathrm{\Sigma }$ by adding the time-dependent, holonomic constraints ${\gamma }^{\alpha }={\widehat{\gamma }}^{\alpha }(t):={\tilde{\gamma }}^{\alpha }(u(t))$. More generally, one can consider a vector-valued control $u(\cdot )=(u^1,\mathrm{\dots },u^M)(\cdot )$ which is directly identified with $\widehat{\gamma }(\cdot )=({\widehat{\gamma }}^1,\mathrm{\dots },{\widehat{\gamma }}^M)(\cdot )$. If one denotes the momenta conjugate...

We give different notions of Liouville forms, generalized Liouville forms and vertical Liouville forms with respect to a locally trivial fibration π:E → M. These notions are linked with those of semi-basic forms and vertical forms. We study the infinitesimal automorphisms of these forms; we also investigate the relations with momentum maps.

The system of zero-pressure gas dynamics conservation laws describes the dynamics of free particles sticking under collision while mass and momentum are conserved. The existence of such solutions was established some time ago. Here we report a uniqueness result that uses the Oleinik entropy condition and a cohesion condition. Both of these conditions are automatically satisfied by solutions obtained in previous existence results. Important tools in the proof of uniqueness are regularizations, generalized...

This Note is the continuation of a previous paper with the same title. Here (Part II) we show that for every choice of the sequence $u{}_a(\cdot )$, ${\mathrm{\Sigma }}_a$'s trajectory $l_a$ after the instant $d+\eta a$ tends in a certain natural sense, as $a\to \mathrm{\infty }$, to a certain geodesic $l$ of $V_d$, with origin at $\left(\overline{q},\overline{u}\right)$. Incidentally $l$ is independent of the choice of applied forces in a neighbourhood of $\left(\overline{q},\overline{u}\right)$ arbitrarily prefixed.

In this Note (which will be followed by a second) we consider a Lagrangian system $\mathrm{\Sigma }$ (possibly without any Lagrangian function) referred to $N+1$ coordinates $q_1\mathrm{\cdots },q_N$, $u$, with $u$ to be used as a control, and precisely to add to $\mathrm{\Sigma }$ a frictionless constraint of the type $u=u\left(t\right)$. Let $\mathrm{\Sigma }$'s (frictionless) constraints be represented by the manifold $V_t$ generally moving in Hertz's space. We also consider an instant $d$ (to be used for certain limit discontinuity-properties), a point $\left(\overline{q},\overline{u}\right)$ of $V_d$, a value $\overline{p}$ for $\mathrm{\Sigma }$'s momentum conjugate...

The notion of an implicit Hamiltonian system-an isotropic mapping H: M → (TM,ω̇) into the tangent bundle endowed with the symplectic structure defined by canonical morphism between tangent and cotangent bundles of M-is studied. The corank one singularities of such systems are classified. Their transversality conditions in the 1-jet space of isotropic mappings are described and the corresponding symplectically invariant algebras of Hamiltonian generating functions are calculated.

The external derivative $d$ on differential manifolds inspires graded operators on complexes of spaces ${\Lambda }^r{g}^{*}$, ${\Lambda }^r{g}^{*}\otimes g$, ${\Lambda }^r{g}^{*}\otimes g^{*}$ stated by $g^{*}$ dual to a Lie algebra $g$. Cohomological properties of these operators are studied in the case of the Lie algebra $g=se\left(3\right)$ of the Lie group of Euclidean motions.

In one of his papers, C. Viterbo defined a distance on the set of Hamiltonian diffeomorphisms of ${ℝ}^{2n}$ endowed with the standard symplectic form ${\omega }_0=dp\wedge dq$. We study the completions of this space for the topology induced by Viterbo’s distance and some others derived from it, we study their different inclusions and give some of their properties. In particular, we give a convergence criterion for these distances that allows us to prove that the completions contain non-ordinary elements, as for example, discontinuous...

We obtain conditions under which a submanifold of a Poisson manifold has an induced Poisson structure, which encompass both the Poisson submanifolds of A. Weinstein [21] and the Poisson structures on the phase space of a mechanical system with kinematic constraints of Van der Schaft and Maschke [20]. Generalizations of these results for submanifolds of a Jacobi manifold are briefly sketched.