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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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4793140186 · Jun 202019922001200920172026
48 results for STAR transformation

Semiparametric STAR model improves mental health data analysis.

problem Overdispersed, zero-inflated, bounded count data in self-reported mental health surveys.
method STAR transformation and rounding of latent Gaussian model, nonparametric transformation estimation, EM algorithm for maximum likelihood.
result Substantial improvements in goodness-of-fit compared to existing models.

We derive a closed formula for a star-product on complex projective space and on the domain SU(n+1)/S(U(1)×U(n))SU(n+1)/S(U(1)\times U(n)) using a completely elementary construction: Starting from the standard star-product of Wick type on Cn+1{0}C^{n+1} \setminus \{ 0 \} and performing a quantum analogue of Marsden-Weinstein reduction, we ca…

1995-03-09abs ↗pdf ↗

The spherical Radon transform on the unit sphere can be regarded as a member of the analytic family of suitably normalized generalized cosine transforms. We derive new formulas for these transforms and apply them to study classes of intersections bodies in convex geometry.

2006-02-24abs ↗pdf ↗

STAR improves equivariant and invariant representation learning by routing projection heads.

problem Redundant feature learning in equivariant and invariant representation learning.
method Soft Task-Aware Routing (STAR) for projection heads specialization.
result Lower canonical correlations between invariant and equivariant embeddings.

Researchers create a star product on a Grassmannian with separation of variables.

problem Constructing a star product with separation of variables on G2,4(C)G_{2,4}(\mathbb{C}).
method Solving recurrence relations using creation and annihilation operators on a Fock space.
result Explicit formula for a star product with separation of variables on G2,4(C)G_{2,4}(\mathbb{C}).

New lower bound shows bandit convex optimization is harder than previously thought.

problem Establishing a lower bound on the minimax expected regret for bandit convex optimization.
method Constructing a hard class of convex functions and analyzing the posterior spread of Fisher information matrices.
result A Ω~(d5/4T)\widetildeΩ(d^{5/4}\sqrt{T}) lower bound on the minimax expected regret.

Neural networks can achieve optimal sample complexity for learning single-index models.

problem Achieving optimal computational-statistical tradeoff in learning Gaussian single-index models.
method Unified gradient-based algorithm for training a two-layer neural network, adaptable to various loss and activation functions.
result Sample complexity of ds/2dd^{s^\star/2} \lor d matches the SQ lower bound up to a polylogarithmic factor.

Study shows computational and statistical gaps in Gaussian Single-Index Models.

problem Statistical and computational trade-offs in high-dimensional regression problems.
method Analysis of SQ and LDP frameworks, partial-trace algorithm.
result Computational algorithms require significantly more samples than information-theoretic limits.

Paper proves conjecture about star-shaped curves evolving under GAPF, but not always preserves star shape.

problem What conditions guarantee global existence of Gage's area-preserving flow for nonconvex initial curves?
method Using Dittberner's singularity analysis theory, constructed a ``flying wing'' curve to show limitations.
result Gage's area-preserving flow does not always preserve star-shapedness of evolving curves.

In this article, we introduce the notion of star-Ricci tensors in the real hypersurfaces of complex quadric QmQ^m. It is proved that there exist no Hopf hypersurfaces in Qm,m3Q^m,m\geq3, with commuting star-Ricci tensor or parallel star-Ricci tensor. As a generalization of star-Einstein metric, star-Ricci solitons on MM

2017-10-29abs ↗pdf ↗

New set-valued star-shaped risk measures introduced for better risk assessment.

problem Improving risk assessment in financial contexts.
method Developed new set-valued star-shaped risk measures and proved their representation theorems.
result Set-valued star-shaped risk measures can be represented as unions of set-valued convex risk measures.

The paper studies dynamic star-shaped risk measures and their representation.

problem Representing dynamic star-shaped risk measures and their properties.
method Representation theorems for dynamic monetary and star-shaped risk measures.
result Dynamic star-shaped risk measures can be represented as the lower envelope of a family of dynamic convex risk measures.

Transformer with denoising diffusion improves probabilistic density estimation.

problem Estimating non-Gaussian and multimodal probability distributions for regression problems.
method Training a denoising diffusion head on top of a Transformer model.
result The model provides reasonable probability density estimation for high-dimensional inputs.

The paper characterizes dynamic return and star-shaped risk measures via BSDEs.

problem Characterizing dynamic return and star-shaped risk measures.
method Characterization of star-shaped functionals and BSDEs.
result Existence of convex BSDEs with non-empty set of supersolutions.

Deform moment map on symplectic connections using star product algebras.

problem Understanding symplectic connections and their deformations.
method Study vector bundle of Fedosov star product algebras, formal connection, curvature, and star product trace.
result Showed star product trace as a formal symplectic form and moment map.

Paper analyzes Birkhoff relaxation for graph alignment, providing theoretical guarantees.

problem Finding vertex correspondence between two graphs to maximize edge overlap.
method Birkhoff relaxation as a convex relaxation of the quadratic assignment problem (QAP).
result Theoretical guarantees on the performance of Birkhoff relaxation under specific conditions.

New partition designs reduce star discrepancy in high-dimensional sampling.

problem Improving the expected star discrepancy in high-dimensional sampling.
method Developed non-equal volume partitions to achieve lower expected star discrepancy.
result Explicit upper bounds for expected star discrepancy under non-equal volume partitions.

We compare the star surgery operations introduced in [KS] to the generalized rational blow-down. We show that star surgery shares the properties that make rational blow-down useful for constructions of small exotic symplectic 4-manifolds. Then we show that star surgery operations provide a strictly more general class o…

2014-07-11abs ↗pdf ↗

Estimates how many times a star appears due to gravitational lensing.

problem Estimating the number of times an observer sees a star due to gravitational lensing.
method Use affine linking numbers to estimate the number of times an observer sees a star.
result Estimates the number of times an observer sees a star due to gravitational lensing.

Improved SGD learning for single index models reduces sample complexity.

problem Learning a single index model with optimal sample complexity.
method Using smoothed loss in online SGD to reduce sample complexity.
result Online SGD with smoothed loss achieves optimal sample complexity of dk/2d^{k^\star/2}.

Let KK be a nontrivial knot in S3S^{3} and t(K)t(K) its tunnel number. For any (p2,q)(p\geq 2,q)-slope in the torus boundary of a closed regular neighborhood of K K in S3S^{3}, denoted by KK^{\star}, it is a nontrivial cable knot in S3S^{3}. Though t(K)t(K)+1t(K^{\star})\leq t(K)+1, Example 1.1 in Section 1 shows that in some cas…

2020-02-18abs ↗pdf ↗

The paper finds at least four prime closed characteristics on star-shaped hypersurfaces in 8D space.

problem Finding prime closed characteristics on compact star-shaped hypersurfaces in 8D space.
method Proved existence of at least four prime closed characteristics for non-degenerate C3C^3 compact star-shaped hypersurfaces in R8\mathbb{R}^{8} without prime closed characteristics of Maslov-type index -1.
result Existence of at least four prime closed characteristics on compact star-shaped hypersurfaces in R8\mathbb{R}^{8}.

This paper connects monetary and star-shaped risk measures by showing their equivalence under certain conditions.

problem Understanding the relationship between monetary and star-shaped risk measures.
method Analyzing the acceptability of 0 and the normalization property.
result Monetary risk measures are only a translation away from star-shapedness under mild conditions.

Given a bordified space, Karlsson defines an incidence geometry of stars at infinity. These stars and their incidence are closely related to well-understood objects when the space is hyperbolic, CAT(0), or a bounded convex domain with the Hilbert metric. A question stemming from Karlsson's original paper was whether or…

2020-01-17abs ↗pdf ↗

The paper proves inequalities for star-shaped and FF-mean convex hypersurfaces in Rn+1\mathbb{R}^{n+1}.

problem Proving geometric inequalities for specific types of hypersurfaces.
method Using anisotropic pp-momentum, perimeter, and volume, the paper derives inequalities for star-shaped and FF-mean convex hypersurfaces.
result The Wulff shape of FF is the unique minimizer of the corresponding functionals among all star-shaped and FF-mean convex sets.

We define the notion of a formal connection for a smooth family of star products with fixed underlying symplectic structure. Such a formal connection allows one to relate star products at different points in the family. This generalizes the formal Hitchin connection introduced by the first author. We establish a necess…

2014-10-07abs ↗pdf ↗

Constructs non-unital monoidal category of contact manifolds and Legendrian correspondence calculus

problem Constructing a non-unital monoidal category of contact manifolds without contact forms
method Developing contact topology without contact forms and defining the star product
result Proving the associativity of the star product and the pentagon axiom

The paper characterizes law-invariant star-shaped risk measures.

problem Understanding and characterizing law-invariant star-shaped risk measures.
method Developed characterizations for positively homogeneous and star-shaped functionals, derived Kusuoka-type representations, and offered representations of general law-invariant star-shaped functionals.
result Characterizations of law-invariant star-shaped functionals, including their connections to Value-at-Risk and Expected Shortfall.

The paper generalizes convex and star-shaped concepts to symplectic spaces and studies variational problems.

problem Generalizing convex and star-shaped concepts to symplectic vector spaces.
method Study of variational problems for symplectically convex and star-shaped curves.
result Extremal points of the variational problem are rigid multiply traversed conics for a range of parameters.

We propose an explicit construction of the deformation quantization of the general second-class constrained system, which is covariant with respect to local coordinates on the phase space. The approach is based on constructing the effective first-class constraint (gauge) system equivalent to the original second-class o…

2001-01-14abs ↗pdf ↗

Study quantization schemes on Kähler manifolds linking star products and BV quantizations.

problem Quantization of structures on Kähler manifolds.
method Construct Fedosov's star products and Batalin-Vilkovisky (BV) quantizations.
result One-loop exactness of BV quantizations, leading to a cochain level formula.