arXiv subjects
Publications and source records attributed to Richard Cushman.
We show that the universal covering space of a connected component of a regular level set of a smooth complex valued function on ${\mathbb{C}}^2$, which is a smooth affine Riemann surface, is ${\mathbb{R}}^2$. This implies that the orbit space of the action of the covering group on ${\mathbb{R}}^2$ is the original affine Riemann surface.
This article gives a detailed description how the holomorphic A5 Hamiltonian determines an affine model of the affine Riemann surface determined by one of its level sets.
This paper constructs a Riemann surface associated to the icosahedron and discusses the geodesics associated to a flat metric on this surface. Because of the icosahedral symmetry, this is a distinguished special case of the example treated in [2].
These notes treat a momentum map associated to the Heisenberg group. We classify the coadjoint orbits of the Heisenberg group and show that the cocycle associated to the momentum map becomes a value of the modulus of a coadjoint orbit. We give a representation theoretic description of this modulus.
We define the notion of a submersion of subcartesian differential spaces and prove some of its properties, which are analogous to those of a submersion in the category of smooth manifolds and smooth mappings.
Our goal is to find a representative of each orbit of the coadjoint action of the generalized Galile group on the dual of its Lie algebra. Our line of argument follows that of Cushman and van der Kallen, but differs in the details.
In this paper we explain how the cocycle of the momentum map of the action of the affine symplectic group on $\mathbb{R}^{2n}$ gives rise to a coadjoint orbit of the odd real symplectic group with a modulus.
We give a representative of every coadjoint orbit of the odd symplectic group. Our argument follows that used for the Poincarè group but the details differ.
In this paper we give geometric conditions so that the integral mapping of a Liouville integrable Hamiltonian system with a focus-focus equilibrium point has scattering monodromy. Using a complex version of the Morse lemma, we show that scattering monodromy is the same as the scattering monodromy of the standard focus-focus system.
We show that a fundamental sandwich algebra has an analogue of a root system of a semisimple Lie algebra. This leads to an analogue of a Weyl group, which we study in another paper.
This paper constructs a Weyl group of a fundamental sandwich algebra.
This paper details a calculation of the second order normal form of the Stark effect Hamiltonian after regularization, using the Kustaanheimo- Stiefel mapping. After reduction we obtain an integrable two degree of freedom system on $S^2_h \times S^2_h$ , which we reduce again to obtain a one degree of freedom Hamiltonian system.
This paper details the geometry of the Kustaanheimo-Stiefel mapping, which regularizes the Hamiltonian of the Kepler problem. It leans heavily on the work of J.-C. van der Meer.
Let $(V,γ)$ be a real finite dimensional vector space with a symmetric bilinear form $γ$ whose kernel is spanned by a nonzero vector. The set of invertible real linear mappings of $(V, γ)$ into itself forms a Lie group called the generalized orthogonal group. This paper finds a unique representative for each orbit of the adjoint action of the generalized orthogonal group on its Lie algebra.
In this paper we give the Bohr-Sommerfeld-Heisenberg quantization of the mathematical pendulum.
In this paper we find a representative of each orbit of the adjoint action of a real affine classical group of its Lie algebra. These orbits are not determined by the usual Jordan invariants of eigenvalues and block sizes, but require a noneigenvalue parameter called a modulus.
In this paper we study differential forms and vector fields on the orbit space of a proper action of a Lie group on a smooth manifold, defining them as multilinear maps on the generators of infinitesimal diffeomorphisms, respectively. This yields an intrinsic view of vector fields and differential forms on the orbit space.
This note shows that the module of smooth vector fields on ${\mathbb{R}}^n$, which are invariant under the linear action of a compact Lie group $G$ is finitely generated by polynomial vector fields on ${\mathbb{R}}^n$ which are invariant under the action of $G$.