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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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265278104 · Jun 202019922001200920172026
48 results for automatic expansion

Bayesian optimization tackles unknown search spaces with automatic expansion.

problem Bayesian optimization in unknown search spaces is challenging.
method Proposes a systematic volume expansion strategy to find points close to the objective function maximum without specifying parameters.
result Derives analytic expressions for expansion triggers and sizes, achieving epsilon-accuracy after a finite number of iterations.

This paper optimizes PCE for efficient surrogate modeling in engineering.

problem Efficiently selecting polynomial regressors for surrogate modeling in computationally expensive models.
method Three state-of-the-art basis-adaptive sparse PCE methods are compared and analyzed.
result Automatic selection of the best solver and basis-adaptive scheme improves surrogate model accuracy.

PVI seeks a posterior that makes predictions closer to true data, not approximating the Bayesian posterior.

problem Finding meaningful posterior distributions under model misspecification.
method Predictive variational inference (PVI) seeks an optimal posterior density for close predictive matching to true data.
result PVI learns a posterior that is not the same as the Bayesian posterior, but is closer to the true data generating process.

Prompted by a recent experiment by Victor Haghani and Richard Dewey, this note generalises the Kelly strategy (optimal for simple investment games with log utility) to a large class of practical utility functions and including the effect of extraneous wealth. A counterintuitive result is proved : for any continuous, co…

2016-11-28abs ↗pdf ↗

New spatiotemporal Besov process improves CT image reconstruction and other inverse problems.

problem Handling abrupt changes and sharp contrasts in spatiotemporal data.
method Generalized Besov process (STBP) with Q-exponential process for temporal correlation.
result STBP outperforms traditional methods in dynamic reconstruction and inverse problems.

The paper derives expansions for Green's operators and resolvents using Hadamard methods.

problem Analyzing normally hyperbolic operators and their Green's functions.
method Hadamard expansions for powers of Green's operators and resolvents.
result Derives expansions involving Hadamard coefficients for advanced/retarded Green's operators.

This work improves texture segmentation by automatically tuning hyperparameters for Total-Variation.

problem The challenge is to automatically select hyperparameters for Total-Variation texture segmentation.
method The approach involves extending Stein's unbiased gradient estimator to handle correlated Gaussian noise, leading to an automatic tuning method.
result The method provides an automatic way to select hyperparameters for Total-Variation texture segmentation.

Analytic torsion expansions for symmetric and complex homogeneous spaces.

problem Calculating the full asymptotic expansion of analytic torsion for various spaces.
method Explicit calculation and comparison with existing results.
result Explicit full asymptotic expansions for symmetric and complex homogeneous spaces.

A new hypergraph expansion method treats vertices and hyperedges equally, improving node classification.

problem Information loss in hypergraph expansions on either vertex or hyperedge level.
method Proposes a new hypergraph formulation named line expansion (LE) that treats vertices and hyperedges symmetrically.
result The proposed line expansion method outperforms state-of-the-art baselines on five hypergraph datasets.

Machine learning predicts US and EuroZone business cycles with high accuracy.

problem Predicting the business cycle phases in US and EuroZone.
method Three machine learning approaches were compared: Multinomial Logistic Regression (MLR) achieved the best results.
result MLR achieved 65.25% accuracy for EuroZone and 75% for US in predicting business cycle phases.

The paper calculates asymptotic expansions for specific types of oscillatory integrals.

problem Analyzing oscillatory integrals with complex phase functions.
method Using asymptotic expansions of simpler phase functions to derive results for more complex cases.
result Explicit computation of coefficients in asymptotic expansions for certain integrals.

In this paper, we investigate the capability of the universal Kriging (UK) model for single-objective global optimization applied within an efficient global optimization (EGO) framework. We implemented this combined UK-EGO framework and studied four variants of the UK methods, that is, a UK with a first-order polynomia…

2018-03-23abs ↗pdf ↗

This work explores functional expansions to handle path dependence in various fields.

problem Path dependence and infinite-dimensional problems in non-Markovian systems.
method Generalizes Wiener series and functional Taylor expansion to handle static and dynamic functionals.
result Elegant separation of functionals from future trajectories in dynamic cases.

In the planar limit of the 't Hooft expansion, the Wilson-loop average in 3d Chern-Simons theory (i.e. the HOMFLY polynomial) depends in a very simple way on representation (the Young diagram), so that the (knot-dependent) Ooguri-Vafa partition function becomes a trivial KP tau-function. We study higher genus correctio…

2013-03-05abs ↗pdf ↗

Paper calculates third coefficient in Kaehler-Einstein metric expansion.

problem Understanding Kaehler-Einstein metrics and their epsilon functions.
method Computes the third coefficient in the TYCZ-expansion of the epsilon function.
result Discovers the vanishing of the third coefficient's significance.

Study on heat trace expansion for thermoelastic Dirichlet-to-Neumann map.

problem Asymptotic expansion of heat trace for thermoelastic Dirichlet-to-Neumann map.
method Provided a method to obtain all coefficients of the asymptotic expansion.
result Explicitly gave the first two coefficients involving volume and total mean curvature of the boundary.

The paper proposes and proves asymptotic expansions for quantum invariants.

problem Quantum invariants and their expansions under varying metrics.
method Asymptotic expansion conjectures for relative Reshetikhin-Turaev, Turaev-Viro invariants and quantum 6j-symbols.
result Proved asymptotic expansions for special cases, showing geometric dependence on metrics.

New method models portfolios with leptokurtic risk factors using Gram-Charlier expansions.

problem Modeling portfolios with excess kurtosis.
method GC-like expansions of the hyperbolic-secant law to account for leptokurtosis.
result Portfolio distribution with risk factors modeled as GC-like expansions of the HS law.

Develops AMITE for analyzing neural network nonlinearities.

problem Addressing difficulties in verification, explainability, and security in neural network analysis.
method Analytically modified integral transform expansion (AMITE) for neural network nonlinearities.
result First to provide six mutually exclusive desired expansion properties.

The validity of an approximation formula for European option prices under a general stochastic volatility model is proved in the light of the Edgeworth expansion for ergodic diffusions. The asymptotic expansion is around the Black-Scholes price and is uniform in bounded payoff func- tions. The result provides a validat…

2010-04-13abs ↗pdf ↗

The paper uses polyhedral expansions to capture the shape of compact metric spaces.

problem Capturing the shape of compact metric spaces using finite approximations.
method Inverse sequences of polyhedra based on finite approximations of a compact metric space.
result Proves the General Principle and computes inverse persistent homology groups.

We quantify predictive uncertainty using the posterior predictive variance.

problem Quantifying uncertainty in predictive models.
method Using the law of total variance, we generate expansions for the posterior predictive variance.
result Identify the main contributors to prediction intervals and quantify term-wise uncertainty.

For any strictly positive martingale S=exp(X)S = \exp(X) for which XX has a characteristic function, we provide an expansion for the implied volatility. This expansion is explicit in the sense that it involves no integrals, but only polynomials in the log strike. We illustrate the versatility of our expansion by computing t…

2012-07-01abs ↗pdf ↗

Researchers calculate the second coefficient in the expansion of a Toeplitz operator.

problem Analyzing the second coefficient in the semi-classical expansion of Toeplitz operators.
method Functional calculus of Toeplitz operators with Reeb vector fields and asymptotic analysis.
result The second coefficient of the expansion is calculated.

Density expansions for hypoelliptic diffusions (X1,...,Xd)(X^1,...,X^d) are revisited. In particular, we are interested in density expansions of the projection (XT1,...,XTl)(X_T^1,...,X_T^l), at time T>0T>0, with ldl \leq d. Global conditions are found which replace the well-known "not-in-cutlocus" condition known from heat-kernel asymptot…

2011-11-10abs ↗pdf ↗

We develop a first order expansion for convex penalized estimators in high-dimensional regression.

problem High-dimensional regression problems with random designs.
method Construct a first order expansion ηη of the penalized estimator β^\hatβ.
result The risk of β^\hatβ is asymptotically the same as the risk of ηη.

Paper proposes a new Taylor moment expansion for non-linear Gaussian filtering and smoothing.

problem Non-linear Gaussian filtering and smoothing in continuous-discrete state-space models.
method Taylor moment expansion (TME) for moment functions directly and in time variable.
result Significantly outperforms state-of-the-art methods in terms of estimation accuracy and numerical stability.