385 research outputs found

### A cocycle on the group of symplectic diffeomorphisms

We define a cocycle on the group of symplectic diffeomorphisms of a
symplectic manifold and investigate its properties. The main applications are
concerned with symplectic actions of discrete groups. For example, we give an
alternative proof of the Polterovich theorem about the distortion of cyclic
subgroups in finitely generated groups of Hamiltonian diffeomorphisms.Comment: 19 pages, no figures, corrected versio

### Inequivalent contact structures on Boothby-Wang 5-manifolds

We consider contact structures on simply-connected 5-manifolds which arise as
circle bundles over simply-connected symplectic 4-manifolds and show that
invariants from contact homology are related to the divisibility of the
canonical class of the symplectic structure. As an application we find new
examples of inequivalent contact structures in the same equivalence class of
almost contact structures with non-zero first Chern class.Comment: 27 pages; to appear in Math. Zeitschrif

### Symplectic geometry on moduli spaces of J-holomorphic curves

Let (M,\omega) be a symplectic manifold, and Sigma a compact Riemann surface.
We define a 2-form on the space of immersed symplectic surfaces in M, and show
that the form is closed and non-degenerate, up to reparametrizations. Then we
give conditions on a compatible almost complex structure J on (M,\omega) that
ensure that the restriction of the form to the moduli space of simple immersed
J-holomorphic Sigma-curves in a homology class A in H_2(M,\Z) is a symplectic
form, and show applications and examples. In particular, we deduce sufficient
conditions for the existence of J-holomorphic Sigma-curves in a given homology
class for a generic J.Comment: 16 page

### On magnetic leaf-wise intersections

In this article we introduce the notion of a magnetic leaf-wise intersection
point which is a generalization of the leaf-wise intersection point with
magnetic effects. We also prove the existence of magnetic leaf-wise
intersection points under certain topological assumptions.Comment: 43 page

### On iterated translated points for contactomorphisms of R^{2n+1} and R^{2n} x S^1

A point q in a contact manifold is called a translated point for a
contactomorphism \phi, with respect to some fixed contact form, if \phi (q) and
q belong to the same Reeb orbit and the contact form is preserved at q. The
problem of existence of translated points is related to the chord conjecture
and to the problem of leafwise coisotropic intersections. In the case of a
compactly supported contactomorphism of R^{2n+1} or R^{2n} x S^1 contact
isotopic to the identity, existence of translated points follows immediately
from Chekanov's theorem on critical points of quasi-functions and Bhupal's
graph construction. In this article we prove that if \phi is positive then
there are infinitely many non-trivial geometrically distinct iterated
translated points, i.e. translated points of some iteration \phi^k. This result
can be seen as a (partial) contact analogue of the result of Viterbo on
existence of infinitely many iterated fixed points for compactly supported
Hamiltonian symplectomorphisms of R^{2n}, and is obtained with generating
functions techniques in the setting of arXiv:0901.3112.Comment: 10 pages, revised version. I removed the discussion on linear growth
of iterated translated points, because it contained a mistake. To appear in
the International Journal of Mathematic

### Topologically Massive Gauge Theory: A Lorentzian Solution

We obtain a lorentzian solution for the topologically massive non-abelian
gauge theory on AdS space by means of a SU(1, 1) gauge transformation of the
previously found abelian solution. There exists a natural scale of length which
is determined by the inverse topological mass. The topological mass is
proportional to the square of the gauge coupling constant. In the topologically
massive electrodynamics the field strength locally determines the gauge
potential up to a closed 1-form via the (anti-)self-duality equation. We
introduce a transformation of the gauge potential using the dual field strength
which can be identified with an abelian gauge transformation. Then we present
the map from the AdS space to the pseudo-sphere including the topological mass.
This is the lorentzian analog of the Hopf map. This map yields a global
decomposition of the AdS space as a trivial circle bundle over the upper
portion of the pseudo-sphere which is the Hyperboloid model for the Lobachevski
geometry. This leads to a reduction of the abelian field equation onto the
pseudo-sphere using a global section of the solution on the AdS space. Then we
discuss the integration of the field equation using the Archimedes map from the
pseudo-sphere to the cylinder over the ideal Poincare circle. We also present a
brief discussion of the holonomy of the gauge potential and the dual-field
strength on the upper portion of the pseudo-sphere.Comment: 23 pages, 1 postscript figur

### The bisymplectomorphism group of a bounded symmetric domain

An Hermitian bounded symmetric domain in a complex vector space, given in its
circled realization, is endowed with two natural symplectic forms: the flat
form and the hyperbolic form. In a similar way, the ambient vector space is
also endowed with two natural symplectic forms: the Fubini-Study form and the
flat form. It has been shown in arXiv:math.DG/0603141 that there exists a
diffeomorphism from the domain to the ambient vector space which puts in
correspondence the above pair of forms. This phenomenon is called symplectic
duality for Hermitian non compact symmetric spaces.
In this article, we first give a different and simpler proof of this fact.
Then, in order to measure the non uniqueness of this symplectic duality map, we
determine the group of bisymplectomorphisms of a bounded symmetric domain, that
is, the group of diffeomorphisms which preserve simultaneously the hyperbolic
and the flat symplectic form. This group is the direct product of the compact
Lie group of linear automorphisms with an infinite-dimensional Abelian group.
This result appears as a kind of Schwarz lemma.Comment: 19 pages. Version 2: minor correction

### Semiclassical almost isometry

Let M be a complex projective manifold, and L an Hermitian ample line bundle
on it. A fundamental theorem of Gang Tian, reproved and strengthened by
Zelditch, implies that the Khaeler form of L can be recovered from the
asymptotics of the projective embeddings associated to large tensor powers of
L. More precisely, with the natural choice of metrics the projective embeddings
associated to the full linear series |kL| are asymptotically symplectic, in the
appropriate rescaled sense. In this article, we ask whether and how this result
extends to the semiclassical setting. Specifically, we relate the Weinstein
symplectic structure on a given isodrastic leaf of half-weighted
Bohr-Sommerfeld Lagrangian submanifolds of M to the asymptotics of the the
pull-back of the Fubini-Study form under the semiclassical projective maps
constructed by Borthwick, Paul and Uribe.Comment: exposition improve

### Local trace formulae and scaling asymptotics in Toeplitz quantization, II

In the spectral theory of positive elliptic operators, an important role is
played by certain smoothing kernels, related to the Fourier transform of the
trace of a wave operator, which may be heuristically interpreted as smoothed
spectral projectors asymptotically drifting to the right of the spectrum. In
the setting of Toeplitz quantization, we consider analogues of these, where the
wave operator is replaced by the Hardy space compression of a linearized
Hamiltonian flow, possibly composed with a family of zeroth order Toeplitz
operators. We study the local asymptotics of these smoothing kernels, and
specifically how they concentrate on the fixed loci of the linearized dynamics.Comment: Typos corrected. Slight expository change

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