activity
20122023
most citedEquivariant indices of Spin-Dirac operators for proper moment maps

14 citations · 70 across the 24 of their papers we have counts for

collaborators

25 papers

math.DG2023

Delocalized eta invariants of the signature operator on G-proper manifolds

Paolo Piazza, Hessel Posthuma, Yanli Song +1

Let be a connected, linear real reductive group and let be a cocompact -proper manifold without boundary. We define delocalized eta invariants associated to a -inve…

math.SG2022★ 3 cited

Symplectic reduction and a Darboux-Moser-Weinstein theorem for Lie algebroids

Yi Lin, Yiannis Loizides, Reyer Sjamaar +1

We extend the Marsden-Weinstein reduction theorem and the Darboux-Moser-Weinstein theorem to symplectic Lie algebroids. We also obtain a coisotropic embedding theorem for symplecti…

math.SG2022

Riemannian foliations and geometric quantization

Yi Lin, Yiannis Loizides, Reyer Sjamaar +1

We introduce geometric quantization for constant rank presymplectic structures with Riemannian null foliation and compact leaf closure space. We prove a quantization-commutes-with-…

math.KT2022

Cartan Motion Group and Orbital Integrals

Yanli Song, Xiang Tang

In this short note, we study the variation of orbital integrals, as traces on the group algebra , under the deformation groupoid. We show that orbital integrals are continuous u…

math.RT2022

On the Connes-Kasparov isomorphism, I: The reduced C*-algebra of a real reductive group and the K-theory of the tempered dual

Pierre Clare, Nigel Higson, Yanli Song +1

This is the first of two papers dedicated to the computation of the reduced C*-algebra of a connected, linear, real reductive group up to Morita equivalence, and the verification o…

math.DG2021★ 2 cited

Higher orbital integrals, rho numbers and index theory

Paolo Piazza, Hessel Posthuma, Yanli Song +1

Let be a connected, linear real reductive group. We give sufficient conditions ensuring the well-definedness of the delocalized eta invariant associated to a Dirac…

math.SG2020★ 3 cited

Log symplectic manifolds and

Yi Lin, Yiannis Loizides, Reyer Sjamaar +1

We show, under an orientation hypothesis, that a log symplectic manifold with simple normal crossing singularities has a stable almost complex structure, and hence is Spin. In…

math.DG2020★ 6 cited

An index theorem for higher orbital integrals

Peter Hochs, Yanli Song, Xiang Tang

Recently, two of the authors of this paper constructed cyclic cocycles on Harish-Chandra's Schwartz algebra of linear reductive Lie groups that detect all information in the -th…

math.KT2019★ 11 cited

Higher Orbit Integrals, Cyclic Cocyles, and K-theory of Reduced Group C*-algebra

Yanli Song, Xiang Tang

Let G be a connected real reductive group. Orbit integrals define traces on the group algebra of G. We introduce a construction of higher orbit integrals in the direction of higher…

math.SG2019★ 2 cited

Geometric quantization of b-symplectic manifolds

Maxim Braverman, Yiannis Loizides, Yanli Song

We introduce a method of geometric quantization for compact -symplectic manifolds in terms of the index of an Atiyah-Patodi-Singer (APS) boundary value problem. We show further…

math.KT2019★ 1 cited

A KK-theoretic perspective on deformed Dirac operators

Yiannis Loizides, Rudy Rodsphon, Yanli Song

We study the index theory of a class of perturbed Dirac operators on non-compact manifolds of the form , where is a Clifford mul…

math.SG2018★ 2 cited

Norm-square localization and the quantization of Hamiltonian loop group spaces

Yiannis Loizides, Yanli Song

In an earlier article we introduced a new definition for the `quantization' of a Hamiltonian loop group space , involving the equivariant -index of a Dirac-type o…

math.DG2018

A geometric formula for multiplicities of -types of tempered representations

Peter Hochs, Yanli Song, Shilin Yu

Let be a connected, linear, real reductive Lie group with compact centre. Let be compact. Under a condition on , which holds in particular if is maximal compact, w…

math.KT2018★ 1 cited

Quantization of Hamiltonian loop group spaces

Yiannis Loizides, Yanli Song

We prove a Fredholm property for spin-c Dirac operators on non-compact manifolds satisfying a certain condition with respect to the action of a semi-direct product gro…

math.SG2017★ 6 cited

Spinor modules for Hamiltonian loop group spaces

Yiannis Loizides, Eckhard Meinrenken, Yanli Song

Let be the loop group of a compact, connected Lie group . We show that the tangent bundle of any proper Hamiltonian -space has a natural completion $\over…

math.RT2017★ 2 cited

A geometric realisation of tempered representations restricted to maximal compact subgroups

Peter Hochs, Yanli Song, Shilin Yu

Let be a connected, linear, real reductive Lie group with compact centre. Let be maximal compact. For a tempered representation of , we realise the restriction $π|…

math.KT2016★ 4 cited

An equivariant index for proper actions II: properties and applications

Peter Hochs, Yanli Song

In the first part of this series, we defined an equivariant index without assuming the group acting or the orbit space of the action to be compact. This allowed us to generalise an…

math.KT2015

An equivariant index for proper actions I

Peter Hochs, Yanli Song

Equivariant indices have previously been defined in cases where either the group or the orbit space in question is compact. In this paper, we develop an equivariant index without a…

math.SG2015

On the Vergne conjecture

Peter Hochs, Yanli Song

Consider a Hamiltonian action by a compact Lie group on a possibly noncompact symplectic manifold. We give a short proof of a geometric formula for decomposition into irreducible r…

math.SG2015★ 9 cited

Dirac operators on quasi-Hamiltonian G-spaces

Yanli Song

We develop notions of twisted spinor bundle and twisted pre-quantum bundle on quasi-Hamiltonian G-spaces. The main result of this paper is that we construct a Dirac operator with i…

math.DG2015★ 14 cited

Equivariant indices of Spin-Dirac operators for proper moment maps

Peter Hochs, Yanli Song

We define an equivariant index of Spin-Dirac operators on possibly noncompact manifolds, acted on by compact, connected Lie groups. The main result in this paper is that the in…

math.DG2014★ 2 cited

An equivariant index for proper actions III: the invariant and discrete series indices

Peter Hochs, Yanli Song

We study two special cases of the equivariant index defined in part I of this series. We apply this index to deformations of Spin-Dirac operators, invariant under actions by po…

math.DG2014

Formal Verlinde Module

Yanli Song

Let G be a compact, simple and simply connected Lie group and $\A$ be an equivariant Dixmier-Douady bundle over G. For any fixed level k, we can define a G-C*-algebra $C_{\A^{k+h}}…

math.SG2014★ 2 cited

A K-homological approach to the quantization commutes with reduction problem

Yanli Song

Kasparov defined a distinguished K-homology fundamental class, so called the Dirac element. We prove a localization formula for the Dirac element in K-homology of crossed product o…