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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

169,341 papers · 148 categories

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3671107142 · Jun 202019922001200920182026
48 results for Dirac kernels

The paper identifies a KK-theoretic obstruction for higher kernel dimensions of Dirac operators.

problem Identifying obstructions for higher kernel dimensions of Dirac operators.
method Using a fibre-wise Dirac operator and topological KK-theory, the paper constructs a family of Fredholm operators and analyzes their Chern classes.
result Chern classes of the KK-class contain information about the kernel of the operators.

Minimal kernels of Dirac operators are studied for maps between manifolds.

problem Finding the minimal dimension of the kernel of Dirac operators for generic maps.
method Analyzing the index of the twisted Dirac operator associated with maps between manifolds.
result A lower bound for the dimension of the kernel of Dirac operators is obtained for generic maps in 2-dimensional manifolds.

The paper proves short-time existence of αα-Dirac-harmonic map flow and applications.

problem Existence of αα-Dirac-harmonic maps from closed surfaces.
method Heat flow for αα-Dirac-harmonic maps, blow-up analysis, density of maps with minimal kernel.
result Existence of nontrivial αα-Dirac-harmonic maps (α1α\geq1) from closed surfaces.

The paper improves L2L^2-estimates for Dirac-Dolbeault operators on complex manifolds.

problem Improving L2L^2-estimates for Dirac-Dolbeault operators on complex manifolds.
method Generalized classical method to handle mixed curvature cases and provided bounds on error terms.
result Full asymptotic expansion for Bergman kernel obtained.

We prove that the kernels of the restrictions of symplectic Dirac or symplectic Dirac-Dolbeault operators on natural subspaces of polynomial valued spinor fields are finite dimensional on a compact symplectic manifold. We compute those kernels for the complex projective spaces. We construct injections of subgroups of t…

2013-07-05abs ↗pdf ↗

Calculates the index of a geometric Dirac operator on manifolds with corners using glueing and Lie groupoid.

problem Calculating the Fredholm index of a geometric Dirac operator with mixed boundary conditions.
method Introduces a glueing construction and Lie groupoid to describe the Dirac operator. Uses a heat kernel method with rescaling to derive an index formula.
result Derives a general index formula of the Atiyah-Singer type.

Paper shows Dirac kernels simplify estimating binary probability distributions.

problem Estimating unknown probability distributions for binary inputs.
method Expanding estimation in Rademacher-Walsh Polynomial basis functions, then showing equivalence to Dirac kernels.
result Dirac kernels can improve computational efficiency and notation for large binary input spaces.

Smooth bundles with rough data maintain Hodge kernel isomorphism.

problem Maintaining Hodge kernel isomorphism for smooth bundles with non-smooth geometric data.
method Analyzing nilpotent differential operators and Hodge-Dirac-type operators under perturbations of geometric data.
result Kernels of Hodge-Dirac operators remain isomorphic under uniform perturbations of geometric data.

Novel boundary integral equations for Dirac operators in 3D Lipschitz domains.

problem Developing equations for Dirac operators in complex 3D domains.
method First-kind boundary integral equations, generalized Garding inequalities, Fredholm operators, finite dimensional kernels, Betti numbers.
result Finite dimensional kernels equal to the sum of Betti numbers, explaining the bilinear forms.

Formula for index of Dirac-type operators on stratified spaces.

problem Calculating the index of Dirac-type operators on complex geometric structures.
method Defined a closed domain, proved self-adjoint and Fredholm properties, established index formula.
result Proved a formula for the Chern character of the index of Dirac-type operators.

Derives a formula for fermion dimensions in spherically symmetric monopole backgrounds.

problem Calculating the dimension of the plane-wave normalizable kernel for massless fermions in spherically symmetric monopole backgrounds.
method Derives a formula for the dimension of the plane-wave normalizable kernel of the Dirac operator for fermions of any representation of SU(N) in the presence of any spherically symmetric monopole background.
result Derives a formula for the dimension of the plane-wave normalizable kernel of the Dirac operator.

Local index theorem for manifolds with Lie structure at infinity using rescaling and renormalized supertrace.

problem Proving an Atiyah-Singer type index theorem for manifolds with Lie structure at infinity.
method Rescaling technique similar to Getzler's, integrating Lie groupoid, functional calculus, heat kernel expansion, Lichnerowicz theorem.
result Proof of a local index theorem for Dirac operators on Lie manifolds.

We obtain a vanishing theorem for the kernel of a Dirac operator on a Clifford module twisted by a sufficiently large power of a line bundle, whose curvature is non-degenerate at any point of the base manifold. In particular, if the base manifold is almost complex, we prove a vanishing theorem for the kernel of a $\spi…

1998-05-27abs ↗pdf ↗

Study an index theorem on manifolds with S^1 action using heat kernels and orbifolds.

problem Index of a transversal Dirac operator on manifolds with S^1 action.
method Probabilistic approach via Feynman-Kac formula, uniform bound estimate.
result Net contributions from lower-dimensional strata vanish identically for certain spin orbifolds.

Let G be a compact, semi-simple Lie group and H a maximal rank reductive subgroup. The irreducible representations of G can be constructed as spaces of harmonic spinors with respect to a Dirac operator on the homogeneous space G/H twisted by bundles associated to the irreducible, possibly projective, representations of…

2000-05-05abs ↗pdf ↗

Generalizing work of W. Müller we investigate the spectral theory for the Dirac operator D on a noncompact manifold X with generalized fibred cusps C(M)=M×[A,[r,g=dr2+φgY+e2crgZ, C(M)=M\times [A,\infty[_r, g= d r^2+ φ^*g_Y+ e^{-2cr}g_Z, at infinity. Here φ:Mh+vYhφ:M^{h+v}\to Y^h is a compact fibre bundle with fibre Z and a distinguished horizontal s…

2001-02-08abs ↗pdf ↗

This article investigates local properties of the further generalized Weierstrass relations for a spin manifold SS immersed in a higher dimensional spin manifold MM from viewpoint of study of submanifold quantum mechanics. We show that kernel of a certain Dirac operator defined over SS, which we call submanifold Dir…

2006-05-10abs ↗pdf ↗

Study of Dirac-Witten operator on Lorentzian manifolds under dominant energy condition.

problem Detecting non-trivial homotopy groups in spaces of initial data under strict dominant energy condition.
method Use index theory and Lorentzian Hitchin's α-invariant to analyze Dirac-Witten operator.
result Kernel of Dirac-Witten operator is non-trivial only if fundamental group is virtually solvable of derived length at most 2.

Let G be a compact connected semisimple Lie group and let H\subset G be a closed connected subgroup such that rank(G)=rank(H) and G/H is a symmetric space. Given an irreducible representation of H, we define a Dirac operator D and determine the representations of G in the kernel of D. Moreover, we show that any irreduc…

2010-08-25abs ↗pdf ↗

Uniform elliptic theory for Dirac operators on orbifold resolutions.

problem Analyzing Dirac operators on orbifold resolutions.
method Viewing orbifolds as conically fibred singular spaces and resolving them by gluing asymptotically conical fibrations.
result Uniform index formula for Dirac operators on orbifold resolutions.

For a Dirac operator DgˉD_{\bar{g}} over a spin compact Riemannian manifold with boundary (Xˉ,gˉ)(\bar{X},\bar{g}), we give a natural construction of the Calderón projector and of the associated Bergman projector on the space of harmonic spinors on Xˉ\bar{X}, and we analyze their Schwartz kernels. Our approach is based on th…

2010-09-16abs ↗pdf ↗

The paper studies Dirac operators on large spectral three-manifolds.

problem Analyzing Dirac operators on spectrally large three-manifolds.
method Non-linear analysis of Seiberg-Witten equations and understanding transversality in monopole Floer homology.
result The locus of flat U(1)-connections on a three-torus where a twisted Dirac operator has kernel is a two-sphere.

We establish the cancellation of the first 2j2j terms in the diagonal asymptotic expansion of the restriction to the (0,2j)(0,2j)-forms of the Bergman kernel associated to the spinc{}^c Dirac operator on high tensor powers of a positive line bundle twisted by a (non necessarily holomorphic) complex vector bundle, over a c…

2012-10-05abs ↗pdf ↗

We consider a general Hermitian holomorphic line bundle LL on a compact complex manifold MM and let pq{\Box}^q_p be the Kodaira Laplacian on (0,q)(0,q) forms with values in LpL^p. The main result is a complete asymptotic expansion for the semi-classically scaled heat kernel exp(upq/p)(x,x)\exp(-u{\Box}^q_p/p)(x,x) along the diagonal…

2014-06-01abs ↗pdf ↗

Let MM be an oriented even-dimensional Riemannian manifold on which a discrete group ΓΓ of orientation-preserving isometries acts freely, so that the quotient X=M/ΓX=M/Γ is compact. We prove a vanishing theorem for a half-kernel of a ΓΓ-invariant Dirac operator on a ΓΓ-equivariant Clifford module over MM, twisted by …

1998-09-24abs ↗pdf ↗