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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.

168,695 papers · 148 categories

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145289434578 · Jun 202019922001200920172026
48 results for Complex Monge--Ampère equation

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 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 ↗

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 ↗

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 ↗

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 ↗

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 ↗

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 ↗

New method combines Monte Carlo and tensor networks for solving complex equations.

problem Solving high-dimensional partial differential equations efficiently.
method Uses Monte Carlo simulations and tensor train sketching for updates and re-estimations.
result Demonstrates versatility and efficacy in solving specific equations.

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 ↗

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 ↗

Study of polygon degeneration to segments in complex space.

problem Understanding the space of polygons degenerated to segments.
method Proved L(n)\mathbb{L}(n) is a smooth submanifold, described its topology, computed geodesics, and quotiented the space.
result Found that L(n)\mathbb{L}(n) and M(n)\mathbb{M}(n) contain straight lines forming a basis of directions in their tangent spaces.

The presentation of supergravity theories of our previous paper "Super-Poincare' algebras, space-times and supergravities (I)" is re-formulated in the language of Berezin-Leites-Kostant theory of supermanifolds. It is also shown that the equations of Cremmer, Julia and Scherk's theory of 11D-supergravity are equivalent…

2011-08-31abs ↗pdf ↗

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.

Reduces a complex hypersurface to a simplified equation with primary invariants.

problem Analyzing Levi degenerate CR manifolds in 5 dimensions.
method Applying Lie's theory, integrating and straightening chains, and using Poincaré-Moser reduction.
result Shows a convergent change of coordinates that simplifies the equation of the manifold.

A neural atlas simplifies 3D geometry simulation by avoiding meshing.

problem Simulation of complex 3D geometries with thin features or non-trivial topology.
method Learned geometric representation of overlapping volumetric coordinate charts, trained from point-cloud or level-set data.
result The learned atlas enables different solvers without re-meshing or re-parametrization.

Let (Mm,g)(M^m,g) be a closed Riemannian manifold (m2)(m\geq 2) of positive scalar curvature and (Nn,h)(N^n,h) any closed manifold. We study the asymptotic behaviour of the second Yamabe constant and the second NN-Yamabe constant of (M×N,g+th)(M\times N,g+th) as tt goes to ++\infty. We obtain that $\lim_{t \to +\infty}Y^2(M\times N,[…

2015-05-05abs ↗pdf ↗

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 aim of this paper is to investigate the differential geometry of immersed surfaces in three-dimensional normed spaces from the viewpoint of affine differential geometry. We endow the surface with a useful Riemannian metric which is closely related to normal curvature, and from this we re-calculate the Minkowski Gau…

2017-09-02abs ↗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.

The paper studies conditions for graphs connecting level sets of harmonic polynomials.

problem Conditions for graphs connecting level sets of harmonic polynomials.
method Algebraic properties and Kempf-Ness functional construction.
result Stability condition equivalent to the existence of a solution to the deformed Hermitian-Yang-Mills equation.

We re-examine classical mechanics with both commuting and anticommuting degrees of freedom. We do this by defining the phase dynamics of a general Lagrangian system as an implicit differential equation in the spirit of Tulczyjew. Rather than parametrising our basic degrees of freedom by a specified Grassmann algebra, w…

2016-06-08abs ↗pdf ↗

In view of A. Andreotti and H. Grauert's vanishing theorem for q-complete domains in C^n, (Théorème de finitude pour la cohomologie des espaces complexes, Bull. Soc. Math. France 90 (1962), 193--259,) we re-prove a vanishing result by J.-P. Sha, (p-convex Riemannian manifolds, Invent. Math. 83 (1986), no. 3, 437--447,)…

2012-11-12abs ↗pdf ↗

We study and generalize in various ways the model of rational expectation (RE) bubbles introduced by Blanchard and Watson in the economic literature. First, bubbles are argued to be the equivalent of Goldstone modes of the fundamental rational pricing equation, associated with the symmetry-breaking introduced by non-va…

2001-02-16abs ↗pdf ↗

Mathematical modeling with Ordinary Differential Equations (ODEs) has proven to be extremely successful in a variety of fields, including biology. However, these models are completely deterministic given a certain set of initial conditions. We convert mathematical ODE models of three benchmark biological systems to Dyn…

2019-10-10abs ↗pdf ↗

Beta-SOD detects and corrects noisy object re-identification using cosine similarity and Beta mixtures.

problem Noisy object re-identification in image datasets.
method Reframed Re-ID as a similarity task, using Siamese networks and Beta mixture models.
result Superior performance in noisy conditions compared to state-of-the-art methods.

We compare the isoperimetric profiles of $S^2 \times \re^3$ and of $S^3 \times \re^2$ with that of a round 5-sphere (of appropriate radius). Then we use this comparison to obtain lower bounds for the Yamabe constants of $S^2 \times \re^3$ and $S^3 \times \re^2$. Explicitly we show that $Y(S^3 \times \re^2, [g_0^3 +dx^2…

2012-02-06abs ↗pdf ↗

We prove that the three-sphere recognition problem lies in the complexity class NP. Our work relies on Thompson's original proof that the problem is decidable [Math. Res. Let., 1994], Casson's version of her algorithm, and recent results of Agol, Hass, and Thurston [ArXiv, 2002].

2004-07-05abs ↗pdf ↗

We mathematically analyze a simple market model where trading at each point in time involves only two agents with the sum of their money being conserved and with neither parties resulting with negative money after the interaction process. The exchange involves random re-distribution among the two players of a fixed fra…

2003-04-30abs ↗pdf ↗

Re-initializing neural networks improves generalization but not as much as other techniques.

problem Understanding when and how re-initialization improves neural network performance.
method Empirical comparison of re-initialization with standard training and various regularization techniques.
result Re-initialization is beneficial for generalization but not as much as other techniques, especially when combined with careful tuning of hyperparameters.