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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.

168,657 papers · 148 categories

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255075100 · May 202619922001200920172026
48 results for E-Z boundaries

We classify ruled minimal surfaces in R3\Bbb R^3 with density ez.e^z. It is showed that there is no noncylindrical ruled minimal surface and there is a family of cylindrical ruled minimal surfaces in R3\Bbb R^3 with density ez.e^z. It is also proved that all translation minimal surfaces are ruled.

2009-01-25abs ↗pdf ↗

We consider harmonic mapsu(z):XzNu(z): \mathcal{X}_z\to N in a fixed homotopy class from Riemann surfaces Xz\mathcal{X}_z of genus g2g\geq 2 varying in the Teichmü{}ller space T\mathcal T to a Riemannian manifold NN with non-positive Hermitian sectional curvature. The energy function E(z)=E(u(z))E(z)=E(u(z)) can be viewed as a funct…

2019-01-15abs ↗pdf ↗

The functional determinant of an elliptic operator with positive, discrete spectrum may be defined as eZ(0)e^{-Z'(0)}, where Z(s)Z(s), the zeta function, is the sum nλns\sum_n^{\infty} λ_n^{-s} analytically continued to ss around the origin. In this paper Z(0)Z'(0) is calculated for the Laplace operator with Dirichlet boundary…

1993-04-08abs ↗pdf ↗

In this paper, we investigate the fixed-point set of an element of a CAT(0) group in its boundary. Suppose that a group GG acts geometrically on a CAT(0) space XX. Let gGg\in G and let Fg\mathcal{F}_g be the fixed-point set of gg in the boundary X\partial X. Then we show that Fg=L(Zg)\mathcal{F}_g=L(Z_g), where ZgZ_g is …

2005-10-24abs ↗pdf ↗

The Fock-Bargmann-Hartogs domain Dn,mD_{n,m} in Cn+m\mathbb{C}^{n+m} is defined by the inequality w2<ez2,\|w\|^2<e^{-\|z\|^2}, where (z,w)Cn×Cm(z,w)\in \mathbb{C}^n\times \mathbb{C}^m, which is an unbounded non-hyperbolic domain in Cn+m\mathbb{C}^{n+m}. This paper mainly consists of three parts. Firstly, we give the explicit expression o…

2018-12-18abs ↗pdf ↗

Motivated by decompositions of spaces that arise in continuous and discrete Morse theory, we describe a so called fibrous decomposition Z = X_0(Y_1)X_1 ... X_{n-1}(Y_n)X_n of a space Z. Among the applications is a succinct formula for the Euler-Poincare characteristic of Z, e(Z) = e(X_0) - e(Y_1) + e(X_1) - ... + e(X_{…

2012-12-01abs ↗pdf ↗

The aim of this article is to generalize in several variables some formulae for Eisenstein series in one variable. For example the formula 2ζ(2k)=(2π)2kB2k(2k)!=Resz=0(1z2k(1ez))2ζ(2k) = (2π)^{2k} \frac{B_{2k}}{(2k)!} = Res_{z=0}(\frac{1}{z^{2k}(1-e^z)}) for the values of zeta functions at even integers in functions of Bernoulli numbers. A. Szenes proved …

1999-03-30abs ↗pdf ↗

FeDXL tackles federated learning for X-risk optimization.

problem Optimizing a family of X-risks with federated learning, where existing algorithms are not applicable.
method Active-passive decomposition framework, federated averaging and merging, novel theoretical analysis.
result FeDXL algorithms for linear and nonlinear ff are developed, with established complexities and improved performance.

Randomly initialized wide neural networks with zero-mean activations are nearly independent, potentially solving AI interpretability limits.

problem Measuring the limits of AI interpretability.
method Randomly initialized neural networks with large width and zero-mean activation functions.
result Neural networks with zero-mean activations are nearly independent, solving the computational no-coincidence conjecture.

We prove a Chern-Lashof type formula computing the expected number of critical points of smooth function on a smooth manifold MM randomly chosen from a finite dimensional subspace VC(M)V\subset C^\infty(M) equipped with a Gaussian probability measure. We then use this formula this formula to find the asymptotics of the e…

2010-08-30abs ↗pdf ↗

TRF uses ternary random features to improve ML performance without extra computation.

problem Improving ML performance with less computation and storage.
method Proposes Ternary Random Features (TRF) for random features compression.
result TRF asymptotically yields the same limiting kernel as original matrices, with improved efficiency.

We consider a stochastic volatility model with Lévy jumps for a log-return process Z=(Zt)t0Z=(Z_{t})_{t\geq 0} of the form Z=U+XZ=U+X, where U=(Ut)t0U=(U_{t})_{t\geq 0} is a classical stochastic volatility process and X=(Xt)t0X=(X_{t})_{t\geq 0} is an independent Lévy process with absolutely continuous Lévy measure νν. Small-time expansio…

2010-09-21abs ↗pdf ↗

Study shows efficient algorithms for noiseless linear regression require quadratic sample complexity in contamination rate.

problem Efficient algorithms for noiseless linear regression under Gaussian covariates with oblivious contamination.
method Formal evidence using Statistical Query complexity.
result Any efficient Statistical Query algorithm requires VSTAT complexity at least Ω(d^(1/2)/α^2).

The paper addresses the expansion of Berezinian and super exterior powers, revealing new insights into supertraces.

problem The breakdown of classical volume elements in supergeometric settings and the need for generalized forms.
method Introduces and analyzes rsr|s-forms, demonstrates the expansion of Ber(E+zA)\mathop{\mathrm{Ber}}(E + z A), and identifies supertraces.
result Intermediate expansions in annular regions encode supertraces of representations on vector spaces.

The study compares parametric and nonparametric models for estimating mean-variance mixtures and finds that nonparametric models perform better.

problem Estimating the distribution of a normal mean-variance mixture under uncertainty.
method Comparison of six parametric mixing laws with a grid nonparametric maximum likelihood estimator, using a paired block bootstrap for score comparison.
result Nonparametric models outperform parametric models in estimating the distribution of a normal mean-variance mixture.

Study tackles distribution shift in combinatorial settings using matrix completion techniques.

problem Tackling distribution shift in combinatorial settings with rigorous statistical guarantees.
method Develops novel algorithms and theoretical results for extrapolating to test distributions not covered in training.
result Achieves bilinear combinatorial extrapolation under gradual spectral decay in high-dimensional data.

Proves well-posedness for Einstein equations with specific boundary conditions.

problem Well-posedness of vacuum Einstein equations with twisted Dirichlet boundary conditions.
method Proves local-in-time well-posedness for the IBVP of the Einstein equations with specified conformal class and scalar densities.
result Proves well-posedness for the Einstein equations with twisted Dirichlet boundary conditions.

We introduce new boundary conditions for differential forms on symplectic manifolds with boundary. These boundary conditions, dependent on the symplectic structure, allows us to write down elliptic boundary value problems for both second-order and fourth-order symplectic Laplacians and establish Hodge theories for the …

2017-10-10abs ↗pdf ↗

Abstracts a construction of boundary triplets for self-adjoint elliptic problems.

problem Computing the index of families of self-adjoint elliptic boundary problems.
method Abstract axiomatic version of boundary triplets and their applications.
result Analytic proof of index theorem and computation of index differences.

The paper studies Ricci flow on manifolds with boundary, proving existence, uniqueness, and boundary conditions preservation.

problem Ricci flow on manifolds with boundary.
method Proving short-time existence and uniqueness of the solution, and showing boundary conditions preservation.
result The flow preserves natural boundary conditions under certain curvature conditions.

Unique compact Fuchsian manifolds with convex boundary are determined by their boundary.

problem Identifying compact Fuchsian manifolds with convex boundaries.
method Proving uniqueness based on the induced path metric on the boundary.
result Compact Fuchsian manifolds with convex boundaries are uniquely determined by the induced path metric on the boundary.

Generalizes Bestvina's Z\mathcal{Z}-boundaries to coarse Z\mathcal{Z}-boundaries.

problem Establishing properties of Z\mathcal{Z}-boundaries for groups.
method Introducing a new concept of a 'coarse Z\mathcal{Z}-boundary' and proving theorems about it.
result Admitting a coarse Z\mathcal{Z}-boundary is a pure quasi-isometry invariant.

Study on quasi-Einstein manifolds with boundary estimates and inequalities.

problem Understanding the geometry of compact quasi-Einstein manifolds with boundary.
method Sharp boundary estimates and characterization theorems for quasi-Einstein manifolds.
result New geometric inequalities and boundary estimates for quasi-Einstein manifolds.

We introduce a new type of boundary for proper geodesic spaces, called the Morse boundary, that is constructed with rays that identify the "hyperbolic directions" in that space. This boundary is a quasi-isometry invariant and thus produces a well-defined boundary for any finitely generated group. In the case of a prope…

2015-02-15abs ↗pdf ↗

Proof of local well-posedness for a specific boundary condition in general relativity.

problem Initial boundary value problem in general relativity with umbilic boundary condition.
method Wave coordinates and key observation of momentum constraint validity for umbilic boundaries.
result Local well-posedness established for the initial boundary value problem.

Study finds rigid properties of boundary-free hypersurfaces in specific data sets.

problem Rigidity of free boundary hypersurfaces in initial data sets with boundary.
method Extending local splitting theorems and applying results on free boundary MOTS.
result Rigidity results for compact free boundary hypersurfaces in initial data sets with boundary.

The paper shows how sublinearly Morse boundaries can be understood through combinatorial methods.

problem Understanding sublinearly Morse boundaries in cubulated groups and CAT(0) cube complexes.
method Combining geometric and combinatorial approaches to analyze sublinearly Morse boundaries.
result Sublinearly Morse boundaries can be described combinatorially and continuously related to Gromov and Roller boundaries.

Homotopy equivalent boundaries of cube complexes are studied.

problem The equivalence of different boundaries of cube complexes.
method Using a partial order on a quotient of the Roller boundary, we obtain the simplicial Roller boundary and show homotopy equivalence among the Tits, simplicial, and simplicial Roller boundaries.
result The Tits, simplicial, and simplicial Roller boundaries are homotopy equivalent.

New examples of non-smoothable homeomorphisms of 4-manifolds with boundary found.

problem Finding non-smoothable homeomorphisms of 4-manifolds with boundary.
method Constructing specific examples of homeomorphisms that fix the boundary and act trivially on homology.
result First examples of non-smoothable self-homeomorphisms of smooth 4-manifolds with boundary.

To every Gromov hyperbolic space X one can associate a space at infinity called the Gromov boundary of X. Gromov showed that quasi-isometries of hyperbolic metric spaces induce homeomorphisms on their boundaries, thus giving rise to a well-defined notion of the boundary of a hyperbolic group. Croke and Kleiner showed t…

2019-09-04abs ↗pdf ↗

We present an introduction to boundary value problems for Dirac-type operators on complete Riemannian manifolds with compact boundary. We introduce a very general class of boundary conditions which contains local elliptic boundary conditions in the sense of Lopatinskij and Shapiro as well as the Atiyah-Patodi-Singer bo…

2013-07-11abs ↗pdf ↗

We establish a moduli space E\mathbb E of stationary vacuum metrics in a spacetime, and set up a well-defined boundary map ΠΠ in E\mathbb E, assigning a metric class with its Bartnik boundary data. Furthermore, we prove the boundary map ΠΠ is Fredholm by showing that the stationary vacuum equations (combined with p…

2018-07-01abs ↗pdf ↗

We define a class of boundary value problems on manifolds with fibered boundary. This class is in a certain sense a deformation between the classical boundary value problems and the Atiyah-Patodi-Singer problems in subspaces. The boundary conditions in this theory are taken as elements of the C^*-algebra generated by p…

2002-07-20abs ↗pdf ↗

Classifies local boundary conditions for Dirac-type operators on manifolds.

problem Determining all local smooth boundary conditions for Dirac-type operators.
method Combining general theory of boundary value problems for Dirac operators and pointwise considerations.
result Classification of local self-adjoint regular boundary conditions for Dirac spinors in dimensions 3 and 4.