Standard static Finsler spacetimes defined and properties studied.
problem Causality in Finslerian geometry of spacetimes.
method Definition and properties of standard static Finsler spacetimes.
result Results connecting causality with Finslerian geometry extending previous work.
We consider Killing vector fields on standard static space-times and obtain equations for a vector field on a standard static space-time to be Killing. We also provide a characterization of Killing vector fields on standard static space-times with compact Riemannian parts.
Essentially, some conditions for the Riemannian factor and the warping function of a standard static space-time are obtained in order to guarantee that no nontrivial warping function on the Riemannian factor can make the standard static space-time Einstein.
Paper proves static triples with specific curvature are standard hemispheres.
problem Proving rigidity of static triples with half harmonic Weyl curvature.
method Analyzes static triples with positive scalar curvature and half harmonic Weyl curvature.
result Proves static triples with half harmonic Weyl curvature and positive scalar curvature are standard hemispheres.
We study solutions to the static vacuum Einstein equations on exterior domains with prescribed metric and mean curvature on the inner boundary. It is proved that for any such boundary data near the standard round boundary data in Euclidean space, there exists a unique AF solution to the static vacuum equations realizin…
Ricci flows on a torus converge to a doubled area static metric.
problem Behavior of Ricci flows on a torus with initial flat metrics.
method Constructing a sequence of Ricci flows with specific curvature decay and initial conditions.
result Ricci flows on a torus converge to a static metric of twice the area, not the standard flat metric.
We classify static manifolds which admit more than one static decomposition whenever a condition on the curvature is fullfilled. For this, we take a standard static vector field and analyze its associated one parameter family of projections onto the base. We show that the base itself is a static manifold and the warpin…
The paper proves conditions for compact vacuum static spaces to be isometric to spheres.
problem Conditions for compact vacuum static spaces to be isometric to spheres.
method Analyzes conditions involving closed conformal vector fields and critical point equations.
result Compact vacuum static spaces with non-trivial closed conformal vector fields are isometric to standard spheres.
Study of hypersurfaces in static spacetimes with curvature bounds.
problem Characterizing hypersurfaces in static spacetimes with curvature constraints.
method Mean curvature and gradient estimates for spacelike hypersurfaces.
result Complete CMC hypersurfaces in static spacetimes are maximal under certain curvature conditions.
In the framework of standard static space times, we state a family of sufficient or necessary conditions for a set of physically reasonable energy and convergence conditions in relativity and related theories. We concentrate our study on questions about the sub-harmonicity of the warping function, the scalar curvature …
Study on static spaces on manifolds with boundary, proving rigidity results.
problem Rigidity of static spaces on compact manifolds with boundary.
method General Böchner type formula to prove rigidity results.
result Positive static triples on standard hemisphere with zero radial Weyl curvature and pinching condition.
In this brief survey, we will remark the interaction among the Hessian tensor on a semi-Riemannian manifold and some of the several questions in Lorentzian (and also in semi-Riemannian) geometry where this 2-covariant tensor is involved. In particular, we deal with the characterization of Killing vector fields and the …
The study proves unique static manifolds with positive scalar curvature and boundary.
problem Characterizing static three-manifolds with boundary and positive scalar curvature.
method Analyzing Ricci curvature bounds and quotient spaces.
result The only orientable quotient of the Nariai static manifold with boundary Nar−1,1(S2) is the only such manifold with connected boundary under certain conditions. Establishes a Penrose-type inequality for static spacetimes.
problem Finding a lower bound on the total mass of static spacetimes.
method Analyzes (n+1)-dimensional asymptotically flat standard static spacetimes under timelike convergence condition.
result Extends Penrose-type inequalities to all dimensions and characterizes equality conditions.
Investigates model risk and semi-static hedging for martingale constrained models.
problem Model risk distributionally robust sensitivities for functionals on the Wasserstein space.
method Introduces distributionally robust problem with semi-static hedging strategies.
result Explicit characterizations of model risk optimal semi-static hedging strategies.
Study compact quasi-Einstein manifolds with boundary estimates.
problem Understanding boundary behavior of quasi-Einstein manifolds.
method Provide boundary estimates and prove isometric properties.
result Compact quasi-Einstein manifolds with connected boundary are isometric to the standard hemisphere.
Paper presents a machine learning algorithm for hedging ETF options, outperforming static hedging methods.
problem Semi-static hedging of ETF options with transaction costs and varying market conditions.
method Data-driven machine learning algorithm considering transaction costs, automated portfolio management, and PnL attribution analysis.
result The static hedging approach outperforms dynamic hedging methods in terms of profit and loss.
QLBS and RLOP methods improve option pricing and hedging performance.
problem Improving option pricing and hedging performance under market frictions.
method Incorporates risk aversion and trading costs into QLBS, proposes RLOP approach.
result RLOP outperforms in dynamic hedging by reducing shortfall probability.
We review geometrical properties of a static spacetime (M,g), including geodesic completeness, causality, standard splittings, compact M, closed geodesics and geodesic connectedness. We pay special attention to the critical quadratic behavior at infinity of the coefficients β, β−1 (β=−g(K,K), being K a …
The paper studies static manifolds with boundary and their properties.
problem Properties of static manifolds with boundary.
method Theorems relating topology and geometry, isoperimetric inequality, uniqueness theorems.
result Characterization of the round ball in Euclidean 3-space as the only scalar-flat static manifold with mean-convex boundary.
Estimates mass of static vacuum metrics with small Bartnik data.
problem Estimating mass of static vacuum metrics with small perturbations.
method Second-order mass estimation using Bartnik data.
result New upper bound on Bartnik mass to fifth order.
Study finds conditions for certain warped product manifolds to be quasi-Einstein.
problem Conditions for quasi-Einstein sequential warped product manifolds.
method Investigated necessary and sufficient conditions for specific types of manifolds.
result Identified conditions for sequential warped product manifolds to be quasi-Einstein.
Study investigates concircular curvature on warped products.
problem Effects of concircular flatness and symmetry on fibre and base manifolds.
method Investigated concircular flat and symmetric warped product manifolds, considered divergence free curvature tensor.
result Results applied to generalized Robertson-Walker and static space-times.
Several authors have recently developed risk-sensitive policy gradient methods that augment the standard expected cost minimization problem with a measure of variability in cost. These studies have focused on specific risk-measures, such as the variance or conditional value at risk (CVaR). In this work, we extend the p…
Deformational structures, in many aspects generalizing standard elasticity theory, are investigated in abstract form. Within free deformational structures we define algebra of deformations, classify them by its special properties, define motions and conformal motions together with deformational decomposition of manifol…
Local well-posedness proved for Bartnik static extension near Schwarzschild spheres.
problem Proving well-posedness for the Bartnik static extension problem near Schwarzschild spheres.
method Introduced a geodesic gauge to formulate governing equations as coupled elliptic and transport equations; used Bochner-measurable functions for transport equations.
result Established local well-posedness for arbitrary Bartnik data near Schwarzschild spheres, including those with small mean curvature.
Framework predicts implied volatility surface without arbitrage.
problem Predicting implied volatility surface without static arbitrage.
method Two-step framework: feature selection and deep neural network (DNN) construction.
result DNN model for surface construction removes static arbitrage and reduces prediction error.
In this note we reduce the problem of geodesic connectedness in a wide class of Gödel type spacetimes to the search of critical points of a functional naturally involved in the study of geodesics in standard static spacetimes. Then, by using some known accurate results on the latter, we improve previous results on the …
New approach reduces unconstrained linear bandits to simpler optimization problems.
problem Unconstrained linear bandits problem.
method Perturbation-based approach combined with comparator-adaptive OLO algorithms.
result First high-probability guarantees for both static and dynamic regret in unconstrained linear bandits.
Fairness criteria may harm over time, contrary to conventional wisdom.
problem The impact of fairness criteria on long-term population well-being.
method Study of fairness criteria in a one-step feedback model, analyzing long-term outcomes.
result Static fairness criteria do not necessarily promote improvement over time and may cause harm.
Study classifies static potentials on 3-manifolds, proving one-dimensionality under specific conditions.
problem Classifying the dimension of static potentials on 3-manifolds.
method Analysis of relative zero sets of static potentials, using Miao and Tam's technique.
result Proves one-dimensionality of static potentials under specific conditions.
New static vacuum metrics confirmed for near Euclidean boundary data.
problem Establishing sufficient conditions for near Euclidean boundary data in static vacuum metrics.
method Using new arguments from studying the conjecture for arbitrary static vacuum metrics.
result Any hypersurface in a dense subfamily is static regular.
The paper studies φ-static perfect fluid space-times in Einstein's General Relativity.
problem Analyzing the geometry of φ-static perfect fluid space-times. method Reduction of Einstein's Field Equations to the factors of a static warped product, introducing φ-curvatures. result Sharp sufficient conditions for a compact φ-SPFST with boundary to be isometric to the standard hemisphere. Study null sectional curvatures in warped product spaces.
problem Investigate null sectional curvatures in warped product spaces.
method Derive formulas for null sectional curvatures of specific warped product models.
result Formulas for null sectional curvatures of various space-time models.
Coral infers generative model structure from code heuristics.
problem Lack of labeled data for complex generative models.
method Static code analysis to infer model structure without ground truth labels.
result Sample complexity scales quasilinearly with heuristics and relations found.
Extends static vacuum metrics with specific boundary conditions.
problem Proving the existence of static vacuum metrics with prescribed boundary data.
method Introducing static regular types (I) and (II), showing local well-posedness, and confirming Bartnik's conjecture.
result Confirms Bartnik's static vacuum extension conjecture for a broad range of boundary conditions.
This paper analyzes diversity measures for streaming data ensembles.
problem Understanding diversity measures for streaming data ensembles.
method Theoretical analysis of diversity measures for streaming data ensembles.
result Analysis provides deeper understanding of diversity and its impact on online ensemble learning.
Investors with extra info can price securities in semi-statically complete models.
problem Pricing securities in markets with dynamic and static trading options.
method Introduces semi-static completeness and uses robust pricing framework.
result Semi-static completeness is equivalent to an extremality property.
Study of 3D vacuum static spaces with specific curvature properties.
problem Classifying 3D vacuum static spaces with certain curvature conditions.
method Used generalized maximum principle to classify 3D spaces.
result Gave a complete classification of 3D complete vacuum static spaces.
Paper studies pseudo-projective tensors on warped products.
problem Characterizing pseudo-projectively flat warped products.
method Analyzes sequential warped products and pseudo-projective tensors.
result Necessary and sufficient conditions for pseudo-projectively flat sequential warped products.
Paper finds exact solutions for static fluids with symmetries.
problem Finding exact solutions for static fluids with symmetries.
method Utilized symmetries to solve Einstein's equation for a perfect fluid on a static manifold.
result Exact solutions found for static fluids with symmetries.
New rigidity theorem on static manifolds with boundary.
problem Static metrics on manifolds with boundary.
method Obata-type rigidity theorem, sufficient geometric conditions.
result Scalar curvature map can be locally surjective at static metrics on manifolds with boundary.
Geometric inequalities for static convex domains in hyperbolic space proved.
problem Proving geometric inequalities for static convex domains in hyperbolic space.
method Using static convexity of flow hypersurfaces, new inequalities are derived.
result New family of geometric inequalities for static convex domains in hyperbolic space.
Establishes a boundary inequality for static manifolds.
problem Functional inequality on the boundary of static manifolds.
method Analyzes the static potential, second fundamental form, and mean curvature.
result Proves a new functional inequality involving these geometric quantities.
The paper investigates geometrical aspects of static spacetime with almost gradient Ricci solitons.
problem Geometrical properties of static spacetime with almost gradient Ricci solitons.
method Analyzing conditions and properties of static spacetime with almost gradient Ricci solitons.
result Conditions and properties of static spacetime with almost gradient Ricci solitons are determined.
The paper classifies vacuum static spaces with harmonic curvature.
problem Classifying vacuum static spaces with harmonic curvature.
method Extending the 4-dimensional work by Kim-Shin, the paper classifies n-dimensional spaces (n≥5). result New counterexamples to the Fischer-Marsden conjecture on compact vacuum static spaces.
The study proves geometric inequalities for static convex domains in static rotationally symmetric spaces.
problem Proving geometric inequalities for static convex domains in static rotationally symmetric spaces.
method Locally constrained curvature flow in a static rotationally symmetric space Nn+1, proving graphical solutions and static convexity preservation. result Proves weighted geometric inequalities for static convex domains close to a slice of Nn+1. Positive mass theorem for tori with scalar curvature bounds.
problem Proving positivity of static quasi-local mass for tori.
method Generalization of Shi-Tam result to 2-tori with specific curvature and scalar curvature bounds.
result Total weighted mean curvature of 2-tori is not greater than that of an isometric embedding into the Kottler manifold.