38 research outputs found
The Spectral Geometry of Einstein Manifolds with Boundary
Let (M,g) be a compact Einstein manifold with smooth boundary. We consider
the spectrum of the p form valued Laplacian with respect to a suitable boundary
condition. We show that certain geometric properties of the boundary may be
spectrally characterized in terms of this data where we fix the Einstein
constant.Comment: 6Page
Moduli spaces of oriented Type A manifolds of dimension at least 3
We examine the moduli space of oriented locally homogeneous manifolds of Type
A which have non-degenerate symmetric Ricci tensor both in the setting of
manifolds with torsion and also in the torsion free setting where the dimension
is at least 3. These exhibit phenomena that is very different than in the case
of surfaces. In dimension 3, we determine all the possible symmetry groups in
the torsion free setting.Comment: 22 page
Berry phase in the simple harmonic oscillator
Berry phase of simple harmonic oscillator is considered in a general
representation. It is shown that, Berry phase which depends on the choice of
representation can be defined under evolution of the half of period of the
classical motions, as well as under evolution of the period. The Berry phases
do {\em not} depend on the mass or angular frequency of the oscillator. The
driven harmonic oscillator is also considered, and the Berry phase is given in
terms of Fourier coefficients of the external force and parameters which
determine the representation.Comment: LaTex, 1 figur
Totally geodesic submanifolds of Damek-Ricci spaces and Einstein hypersurfaces of the Cayley projective plane
We classify totally geodesic submanifolds of Damek-Ricci spaces and show that
they are either homogeneous (such submanifolds are known to be "smaller"
Damek-Ricci spaces) or isometric to rank-one symmetric spaces of negative
curvature. As a by-product, we obtain that a totally geodesic submanifold of
any known harmonic manifold is by itself harmonic. We prove that the Cayley
hyperbolic plane admits no Einstein hypersurfaces and that the only Einstein
hypersurfaces in the Cayley projective plane are geodesic spheres of a
particular radius; this completes the classification of Einstein hypersurfaces
in rank-one symmetric spaces. We also show that if a -stein space admits a
-stein hypersurface, then both are of constant curvature, under some
additional conditions.Comment: 17 page
A one-parameter family of totally umbilical hyperspheres in the nearly Kaehler 6-sphere
We discuss two kinds of almost contact metric structures on a one-parameter
family of totally umbilical hyperspheres in the nearly Kaehler unit 6-sphere.Comment: 13 page
Heat content asymptotics for spectral boundary conditions
We study the short time heat content asymptotics for spectral boundary
conditions. The heat content coefficients are shown to be non-local and some
preliminary results concerning the structure of the first few terms are given.Comment: 10 pages, LaTe
Characterizing the harmonic manifolds by the eigenfunctions of the Laplacian
The space forms, the complex hyperbolic spaces and the quaternionic
hyperbolic spaces are characterized as the harmonic manifolds with specific
radial eigenfunctions of the Laplacian.Comment: 8 page
A remark concerning universal curvature identities on 4-dimensional Riemannian manifolds
We shall prove the universality of the curvature identity for the
4-dimensional Riemannian manifold using a different method than that used by
Gilkey, Park, and Sekigawa \cite{GPS}.Comment: 8 page
Curvature identities on contact metric manifolds and their applications
We study curvature identities on contact metric manifolds on the geometry of
the corresponding almost K\"aehler cones, and we provide applications of the
derived curvature identities.Comment: 14 page
Hermitian structures on the product of Sasakian manifolds
We investigate the curvature properties of a two-parameter family of
Hermitian structures on the product of two Sasakian manifolds, as well as
intermediate relations. We give a necessary and sufficient condition for a
Hermitian structure belonging to the family to be Einstein and provide concrete
examples.Comment: 12 page