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arXiv research

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.

168,742 papers · 148 categories

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142285427569 · Jun 202019922001200920172026
48 results for complex Monge-Ampère flow

We establish a stability result for elliptic and parabolic complex Monge-Amp{è}re equations on compact K{ä}hler manifolds, which applies in particular to the K{ä}hler-Ricci flow. Dedicated to Jean-Pierre Demailly on the occasion of his 60th birthday.

2018-10-04abs ↗pdf ↗

We develop a parabolic pluripotential theory on compact K{ä}hler manifolds, defining and studying weak solutions to degenerate parabolic complex Monge-Amp{è}re equations. We provide a parabolic analogue of the celebrated Bedford-Taylor theory and apply it to the study of the K{ä}hler-Ricci flow on varieties with log te…

2018-10-04abs ↗pdf ↗

Continuity of complex Monge-Ampère potentials on Kähler manifolds.

problem Continuity of solutions to complex Monge-Ampère equations on compact Kähler manifolds.
method Extending DiNezza-Lu's approach to big cohomology classes, proving continuity on Zariski open sets.
result Singular Kähler-Einstein metrics have continuous potentials on the ample locus outside of the non-klt part.

We obtain a necessary and sufficient condition of existence of a K{ä}hler-Einstein metric on a G×GG\times G-equivariant Fano compactification of a complex connected reductive group GG in terms of the associated polytope. This condition is not equivalent to the vanishing of the Futaki invariant. The proof relies on the …

2015-10-26abs ↗pdf ↗

The paper studies mean curvature flow of Lagrangian graphs in pseudo-Euclidean space.

problem Mean curvature flow of Lagrangian graphs in pseudo-Euclidean space.
method Analyzes the parabolic equation and Monge-Ampère type equation, proving smooth solutions and convergence to self-expanding solutions.
result Smooth solutions u(x,t)u(x,t) for specific nonlinear equations and convergence to self-expanding solutions.

In this paper, we investigate two hyperbolic flows obtained by adding forcing terms in direction of the position vector to the hyperbolic mean curvature flows in \cite{klw,hdl}. For the first hyperbolic flow, as in \cite{klw}, by using support function, we reduce it to a hyperbolic Monge-Ampeˋ\grave{\rm{e}}re equation …

2012-03-12abs ↗pdf ↗

N. V. Efimov \cite{Ef1} proved that there is no complete, smooth surface in R3\R^3 with uniformly negative curvature. We extend this to isometric immersions in a 3-manifold with pinched curvature: if M3M^3 has sectional curvature between two constants K2K_2 and K3K_3, then there exists K1<min(K2,0)K_1 < \min(K_2, 0) such that $M…

1999-12-13abs ↗pdf ↗

We propose a numerical method for solving high dimensional fully nonlinear partial differential equations (PDEs). Our algorithm estimates simultaneously by backward time induction the solution and its gradient by multi-layer neural networks, while the Hessian is approximated by automatic differentiation of the gradient…

2019-07-31abs ↗pdf ↗

We come up with infinite-dimensional prequantum line bundles and moment map interpretations of three different sets of equations - the generalised Monge-Amp`ere equation, the almost Hitchin system, and the Calabi-Yang-Mills equations. These are all perturbations of already existing equations. Our construction for the g…

2017-02-03abs ↗pdf ↗

In this paper, we study the backward Ricci flow on locally homogeneous 3-manifolds. We describe the long time behavior and show that, typically and after a proper re-scaling, there is convergence to a sub-Riemannian geometry. A similar behavior was observed by the authors in the case of the cross curvature flow.

2008-10-18abs ↗pdf ↗

We investigate how to obtain various flows of Kähler metrics on a fixed manifold as variations of Kähler reductions of a metric satisfying a given static equation on a higher dimensional manifold. We identify static equations that induce the geodesic equation for the Mabuchi's metric, the Calabi flow, the pseudo-Calabi…

2013-04-21abs ↗pdf ↗

It is natural to ask: what kinds of matrices satisfy the Restricted Eigenvalue (RE) condition? In this paper, we associate the RE condition (Bickel-Ritov-Tsybakov 09) with the complexity of a subset of the sphere in Rp\R^p, where pp is the dimensionality of the data, and show that a class of random matrices with indep…

2009-12-21abs ↗pdf ↗

Given a complex analytic function f on a Whitney stratified complex analytic variety of complex dimension n, whose real part Re(f) is Morse, we prove the existence of a stratified gradient-like vector field for Re(f) such that the unstable set of a critical point p on a stratum S of complex dimension s has real dimensi…

2009-08-13abs ↗pdf ↗

Study uses neural networks to predict wall quantities in turbulent flows.

problem Predicting wall quantities in turbulent open channel flows.
method Training convolutional neural networks (FCN) and a proposed R-Net architecture to predict wall-shear-stress and wall pressure.
result R-Net architecture performs better and predicts wall quantities with around 10% error.

Study eigenvalues of Laplace operator on specific 3D manifolds under Ricci flow.

problem Analyze eigenvalues of Laplace operator with potential under backward Ricci flow.
method Use backward Ricci flow on locally homogeneous 3-manifolds, derive bounds and convergence results.
result Eigenvalue λ+(t)λ^{+}(t) approaches zero as flow converges to sub-Riemannian geometry.

Let X be a closed manifold with zero Euler characteristic, and let f: X --> S^1 be a circle-valued Morse function. We define an invariant I which counts closed orbits of the gradient of f, together with flow lines between the critical points. We show that our invariant equals a form of topological Reidemeister torsion …

1997-06-24abs ↗pdf ↗

In [Centro-affine invariants for smooth convex bodies, Int. Math. Res. Notices. doi: 10.1093/imrn/rnr110, 2011] Stancu introduced a family of centro-affine normal flows, pp-flow, for 1p<.1\leq p<\infty. Here we investigate the asymptotic behavior of the planar pp-flow for p=p=\infty in the class of smooth, origin-symme…

2013-12-17abs ↗pdf ↗

Convolutional networks predict turbulence from wall quantities.

problem Predicting turbulence fields from wall-shear-stress components and wall pressure.
method Two CNN models: FCN and FCN-POD, trained on DNS data.
result FCN and FCN-POD models outperform EPOD in predicting turbulence fields.

The study finds conditions for a third rank Killing tensor field on a 2D Riemannian torus.

problem Conditions for the existence of a third rank Killing tensor field on a 2D Riemannian torus.
method Analyzes the metric of the torus and uses Fourier coefficients to derive conditions for the function λ.
result Equations relating Fourier coefficients of the function λ determine the existence of a third rank Killing tensor field.

Study on colored Jones polynomial of figure-eight knot for complex parameters.

problem Asymptotic behavior of colored Jones polynomial for figure-eight knot.
method Analyzing the asymptotic growth rate of the polynomial for complex parameters with small imaginary part.
result Growth rate of polynomial is related to the Chern-Simons invariant for large real part of the parameter and to the reciprocal of Alexander polynomial for small real part.

The paper studies practical estimation and interpretation of Rényi transfer entropy.

problem Challenges in accurately estimating and interpreting Rényi transfer entropy.
method Systematic study of k-nearest neighbor estimator for Rényi entropy and transfer entropy.
result Effective estimates of effective Rényi transfer entropy can accurately capture directional information flow.

The increasing complexity of the power grid, due to higher penetration of distributed resources and the growing availability of interconnected, distributed metering devices re- quires novel tools for providing a unified and consistent view of the system. A computational framework for power systems data fusion, based on…

2017-05-24abs ↗pdf ↗

GLASS Flows improves flow and diffusion model performance by optimizing sampling efficiency.

problem Efficiency bottleneck in sampling Markov transitions for flow and diffusion models.
method Introduces GLASS Flows, a new sampling paradigm that simulates a 'flow matching model within a flow matching model' to sample Markov transitions efficiently.
result Eliminates the trade-off between stochastic evolution and efficiency in large-scale text-to-image models.

Parabolic geometric flows have the property of smoothing for short time however, over long time, singularities are typically unavoidable, can be very nasty and may be impossible to classify. The idea of this paper is that, by bringing in the dynamical properties of the flow, we obtain also smoothing for long time for g…

2018-08-09abs ↗pdf ↗

Study reduces complexity and uncertainty in human atrial cell models.

problem Uncertainty in parameter estimates from gating kinetics models.
method Approximate Bayesian computation to re-calibrate models, investigate two approaches: more complete datasets and less complex formulations.
result Less complex model with fewer parameters gives better fit and lower uncertainty.

In this note we prove the following result: Let XX be a complete, connected 4-manifold with uniformly positive isotropic curvature, with bounded geometry and with no essential incompressible space form. Then XX is diffeomorphic to S4\mathbb{S}^4, or RP4\mathbb{RP}^4, or S3×S1\mathbb{S}^3\times \mathbb{S}^1, or $\mathbb{S…

2011-08-15abs ↗pdf ↗

The paper studies a special Grassmannian space and shows it's an orbit of a unitary group.

problem Investigating a specific Grassmannian space of infinite-dimensional subspaces.
method Analyzing the restricted pp-Schatten class Grassmannian and showing it's an affine coadjoint orbit of a unitary group.
result The restricted pp-Schatten class Grassmannian is shown to be an affine coadjoint orbit of an infinite-dimensional restricted unitary group.

In this short paper, we re-derive the Bochner formula for the Laplacian by considering local variations of volume. The derivation is rooted in the fact that the Laplacian of a function measures the volume variation along the flow of the gradient vector of the function. Possible extensions of this approach/technique are…

2013-06-17abs ↗pdf ↗

RDL-Net improves speech enhancement with fewer parameters and better performance.

problem Improving speech enhancement with fewer parameters and better performance.
method Proposes RDL-Net, a CNN combining residual and dense aggregations without over-allocating parameters.
result RDL-Net achieves higher speech enhancement performance with fewer parameters and lower computational requirements.

The geometric constructions are elaborated on (semi) Riemannian manifolds and vector bundles provided with nonintegrable distributions defining nonlinear connection structures induced canonically by metric tensors. Such spaces are called nonholonomic manifolds and described by two equivalent linear connections also ind…

2007-04-16abs ↗pdf ↗

The Willmore flow is well known problem from the differential geometry. It minimizes the Willmore functional defined as integral of the mean-curvature square over given manifold. For the graph formulation, we derive modification of the Willmore flow with anisotropic mean curvature. We define the weak solution and we pr…

2011-11-13abs ↗pdf ↗

The paper provides approximation guarantees for neural networks trained with gradient flow.

problem Approximating neural networks trained with gradient flow in continuous L2(Sd1)L_2(\mathbb{S}^{d-1})-norm.
method NTK argument for non-convex second but last layer, under-parametrized regime.
result Gradient flow convergence guarantees for neural networks under Sobolev smoothness assumptions.

New method for inference on covariates in NMF with random effects.

problem Formal inference for covariate effects in NMF with non-negativity constraints.
method NMF-RE model with random effects, ridge updates, df-based cap, asymptotic linearization, wild bootstrap.
result Valid inference on covariates with non-negativity constraint, avoiding degeneracy.

New framework transforms labeled datasets for various machine learning tasks.

problem Lack of principled methods to transform labeled datasets.
method Wasserstein gradient flows in probability space for optimization of data-generating distributions.
result Framework can impose constraints, adapt for transfer learning, or re-purpose models.

The study identifies conjugate and cut points in ideal fluid motion configurations.

problem Understanding stability and re-convergence of fluid configurations.
method Existence and non-existence of conjugate points in specific fluid configurations, using geometric and physical analysis.
result Existence of conjugate points in Kolmogorov flows and non-existence in Arnold steady states.