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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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275480107 · Jun 202019922001200920172026
48 results for Partial Convexification

Partial convexification improves tractability of low-rank spectral optimization problems.

problem Minimizing linear objectives subject to matrix inequalities and low-rank constraints.
method Partial convexification of the domain set, deriving rank bounds, and developing a column generation algorithm.
result The partial convexification LSOP-R is equivalent to the original LSOP under certain conditions and yields high-quality solutions.

We introduce normalized nonnegative models (NNM) for explorative data analysis. NNMs are partial convexifications of models from probability theory. We demonstrate their value at the example of item recommendation. We show that NNM-based recommender systems satisfy three criteria that all recommender systems should ide…

2015-11-15abs ↗pdf ↗

The paper extends a neural model to estimate uncertainty in multi-interaction trajectory reconstruction.

problem Lack of uncertainty estimation in neural models for multi-interaction trajectory reconstruction.
method Extended Factorised Neural Relational Inference model to output mean and standard deviation for each component of the phase space vector, using various loss functions.
result Demonstrated the importance of physical meaning of variables and existence of local minima during training.

The paper tackles fairness in forecasting and learning linear dynamical systems.

problem Under-representation bias in training data for multiple subgroups.
method Introducing subgroup-fair and instant-fair learning of LDS from multiple trajectories of varying lengths, using hierarchies of convexifications of non-commutative polynomial optimisation problems.
result Empirical results show both the beneficial impact of fairness considerations on statistical performance and encouraging effects of exploiting sparsity on run time.

Signal estimation problems with smoothness and sparsity priors can be naturally modeled as quadratic optimization with 0\ell_0-"norm" constraints. Since such problems are non-convex and hard-to-solve, the standard approach is, instead, to tackle their convex surrogates based on 1\ell_1-norm relaxations. In this paper…

2018-11-06abs ↗pdf ↗

Proposes a method to solve deep neural networks' local minimum problem.

problem Local minimum problem in deep neural networks training.
method Transforms cross-entropy loss into risk-averse error criterion, adjusts RSI, and uses convexity region.
result Trained deep learning machine is expected to be inside a global minimum's attraction basin.

Traditionally, most complex intelligence architectures are extremely non-convex, which could not be well performed by convex optimization. However, this paper decomposes complex structures into three types of nodes: operators, algorithms and functions. Iteratively, propagating from node to node along edge, we prove tha…

2018-01-09abs ↗pdf ↗

Regularized empirical risk minimization with constrained labels (in contrast to fixed labels) is a remarkably general abstraction of learning. For common loss and regularization functions, this optimization problem assumes the form of a mixed integer program (MIP) whose objective function is non-convex. In this form, t…

2016-02-22abs ↗pdf ↗

Given a C1C^1 planes distribution PTP_T on all Rm{\mathbb R}^m we consider {\em horizontal αα-harmonic maps}, α1/2α\ge 1/2, with respect to such a distribution. These are maps uHα(Rk,Rm)u\in H^α({\mathbb R}^k,{\mathbb R}^m) satisfying PTu=uP_T\nabla u=\nabla u and PT(u)(Δ)αu=0P_T(u)(-Δ)^αu=0 in D(Rk).{\mathcal D}'({\mathbb R}^k). If the distrib…

2016-04-19abs ↗pdf ↗

DCCNNs reduce computational overhead and ambiguity in convolutional neural networks.

problem Reducing computational overhead and ambiguity in convolutional neural networks.
method Introducing a primal learning problem and constructing a dual convex training program, using Fenchel conjugates and Karush-Kuhn-Tucker conditions.
result Eliminates ambiguity and reduces computational overhead in constructing a large kernel matrix.

Sparse regression models are increasingly prevalent due to their ease of interpretability and superior out-of-sample performance. However, the exact model of sparse regression with an 0\ell_0 constraint restricting the support of the estimators is a challenging (\NP-hard) non-convex optimization problem. In this paper…

2019-01-29abs ↗pdf ↗

New bounds show complexity of adversarial decision making.

problem Understanding sample efficiency in adversarial decision making.
method New upper and lower bounds on Decision-Estimation Coefficient.
result Decision-Estimation Coefficient is necessary and sufficient for low regret in adversarial decision making.

The aim of this paper is to develop a general framework for training neural networks (NNs) in a distributed environment, where training data is partitioned over a set of agents that communicate with each other through a sparse, possibly time-varying, connectivity pattern. In such distributed scenario, the training prob…

2016-10-24abs ↗pdf ↗

An differential field (F;1,...,m)(F;\partial_1,...,\partial_m) of characteristic zero, a subgroup HH of affine group GL(n,C)Cn GL(n,C)\propto C^n with respect to its identical representation in FnF^n and the following two fields of differential rational functions in x=(x1,x2,...,xn)x=(x_1,x_2,...,x_n)-column vector, $$C< x, \partial >^H=\{f^{\part…

2006-09-09abs ↗pdf ↗

The L2L^2-\partial\overline\partial-Lemma is extended to complete Kähler manifolds with a gap in the spectrum.

problem Extending the L2L^2-\partial\overline\partial-Lemma to non-compact Kähler manifolds.
method Proving the L2L^2-\partial\overline\partial-Lemma on complete Kähler manifolds with a gap in the spectrum.
result The L2L^2-\partial\overline\partial-Lemma is generalized to complete Kähler manifolds.

Sharp Hölder regularity found for complex Frobenius theorem coordinates.

problem Finding optimal Hölder-Zygmund regularity for complex Frobenius theorem coordinates.
method Analyzing necessary and sufficient conditions for coordinate charts achieving the theorem's structure.
result The optimal Hölder-Zygmund regularity for coordinate charts is shown to be αα.

In a recent paper~\cite{DDL10} we studied basic properties of partial immersions and partially free maps, a generalization of free maps introduced first by Gromov in~\cite{Gro70}. In this short note we show how to build partially free maps out of partial immersions and use this fact to prove that the partially free map…

2010-10-26abs ↗pdf ↗

Study cohomologies of complex manifolds with symplectic forms and their stability.

problem Analyzing cohomologies of complex manifolds with symplectic forms.
method Investigate the Hard Lefschetz Condition on Dolbeault cohomology groups using a double complex.
result Stability of the Λ\overline{\partial}\, \overline{\partial}^Λ-Lemma under small deformations of ωω but not under complex structure.

Let MM be a surface sum of 3-manifolds M1M_1 and M2M_2 along a bounded connected surface FF and i\partial_i be the component of Mi\partial M_i containing FF. If MiM_i has a high distance Heegaard splitting, then any minimal Heegaard splitting of MM is the amalgamation of those of M1,M2M^1, M^2 and MM^*, where $M^i=M…

2008-06-18abs ↗pdf ↗

We present a simple, flexible, and general framework titled Partial Registration Network (PRNet), for partial-to-partial point cloud registration. Inspired by recently-proposed learning-based methods for registration, we use deep networks to tackle non-convexity of the alignment and partial correspondence problems. Whi…

2019-10-27abs ↗pdf ↗

The paper studies maps from pseudo-Hermitian to Kähler manifolds, proving harmonic map properties.

problem Analyzing maps between pseudo-Hermitian and Kähler manifolds.
method Investigates partial energy functionals and critical maps, proving foliated results for b\overline{\partial}_{b}- and b\partial_{b}-harmonic maps.
result Generalizes Siu's holomorphicity result to b\overline{\partial}_{b}- and b\partial_{b}-harmonic maps.

The paper proves Hodge decompositions and partial bar partial lemmas for G2 and Calabi-Yau manifolds.

problem Proving Hodge decompositions and partial bar partial lemmas for G2 and Calabi-Yau manifolds.
method Defining cohomology spaces analogous to Bott-Chern cohomology and relating them to harmonic forms on the manifolds.
result Geometric interpretation of cohomology classes in terms of submanifolds and gerbes for G2 manifolds.

The paper studies holomorphic Poisson manifolds and their deformations under specific cohomology conditions.

problem Understanding deformations of holomorphic Poisson manifolds under certain cohomological assumptions.
method Investigates properties of Koszul-Brylinski homology and Dolbeault cohomology, proving formality of a DGLA.
result The DGLA is shown to be formal, and Maurer-Cartan elements induce complex structure deformations.

The paper characterizes when the \partial \overline{\partial}-lemma holds for twistor spaces.

problem Characterizing the \partial \overline{\partial}-lemma for twistor spaces.
method Study Bott-Chern and Aeppli cohomologies of twistor spaces.
result Explicit computation of Dolbeault cohomology for flat torus twistor space.

Let MM be a compact hypersurface with boundary M=D1D2\partial M=\partial D_1 \cup \partial D_2, D1Π1\partial D_1 \subset Π_1, D2Π2\partial D_2 \subset Π_2, Π1Π_1 and Π2Π_2 two parallel hyperplanes in Rn+1\mathbb{R}^{n+1} (n2n \geq 2). Suppose that MM is contained in the slab determined by these hyperplanes and that the mean cu…

2016-01-12abs ↗pdf ↗

The paper studies deformations of Calabi-Yau manifolds using Gauduchon metrics.

problem Deformations of Calabi-Yau manifolds under co-polarised conditions.
method Analyzes local deformations of Calabi-Yau ˉ\partial\bar{\partial}-manifolds using Gauduchon metrics and constructs a new hphp-HS form.
result Proves the pp-SKT hh-ˉ\partial\bar{\partial}-property is deformation open.

Paper tackles distribution matching by partially matching distributions, achieving robust results.

problem Robustly aligning two probability distributions.
method Developed a partial Wasserstein adversarial network (PWAN) to efficiently approximate the partial Wasserstein-1 (PW) discrepancy.
result The PWAN effectively produces highly robust matching results, outperforming state-of-the-art methods.

On a compact ˉ\partial\bar\partial-manifold XX, one has the Hodge decomposition: the de Rham cohomology groups split into subspaces of pure-type classes as HdRk(X)=p+q=kHp,q(X)H_{dR}^k (X)=\oplus_{p+q=k}H^{p,\,q}(X), where the Hp,q(X)H^{p,\,q}(X) are canonically isomorphic to the Dolbeault cohomology groups Hˉp,q(X)H_{\bar\partial}^{p,\,q}(X). F…

2020-01-07abs ↗pdf ↗

Study on 44-dimensional almost-Hermitian manifolds, proving \overline\partial-harmonic forms invariant under certain metrics.

problem Proving \overline\partial-harmonic forms are topological invariants for specific metrics on 44-dimensional almost-Hermitian manifolds.
method Analyzing \overline\partial-Laplacian and using globally conformally Kähler and strictly locally conformally Kähler metrics.
result Dimension of \overline\partial-harmonic (1,1)(1,1)-forms is a topological invariant, answering Kodaira and Spencer's problem.

We consider partial matchings, which are finite graphs consisting of edges and vertices of degree zero or one. We consider transformations between two states of partial matchings. We introduce a method of presenting a transformation between partial matchings. We introduce the notion of the lattice presentation of a par…

2017-05-21abs ↗pdf ↗

It is shown that any smooth strictly convex global solution of det(2uξiξj)=exp{i=1ndiuξid0},\det(\frac{\partial^{2}u}{\partial ξ_{i}\partial ξ_{j}}) = \exp \left\{-\sum_{i=1}^n d_i \frac{\partial u}{\partial ξ_{i}} - d_0\right\}, where d0d_0, d1d_1,...,dnd_n are constants, must be a quadratic polynomial. This extends a well-known theorem of Jö…

2007-10-19abs ↗pdf ↗

New theorems on Hodge numbers and Kähler structures derived from complex differential forms.

problem Deformation invariance and local stability of Hodge numbers and Kähler structures.
method Using the exponential operator and power series method, the approach focuses on dd-closed extensions and foliated cases.
result Local stabilities of transversely pp-Kähler structures and new theorems on Hodge numbers.

Study shows partial hyperbolicity leads to Anosov dynamics in 3-manifolds.

problem Understanding dynamics in hyperbolic 3-manifolds and Seifert manifolds.
method Classification of partially hyperbolic diffeomorphisms and pseudo-Anosov dynamics.
result Complete classification of partially hyperbolic diffeomorphisms in hyperbolic 3-manifolds and Seifert manifolds.

We fully describe the horofunction boundary hL2\partial_h L_2 with the word metric associated with the generating set {t,at}\{t,at\} (i.e the metric arising in the Diestel-Leader graph DL(2,2)\text{DL}(2,2)). The visual boundary L2\partial_\infty L_2 with this metric is a subset of hL2\partial_h L_2. Although $\partial_\infty L_2…

2014-10-31abs ↗pdf ↗

New algorithm improves reinforcement learning from partial observations.

problem Inferior performance of algorithms in real-world reinforcement learning due to partial observability.
method Representation-based approach to POMDPs, leading to a tractable algorithm.
result Empirically demonstrates superior performance with partial observations.