Results 131 to 140 of about 2,879,792 (277)
Is the maximal function of a Lipschitz function continuous? [PDF]
, 1999 We examine the action of the maximal operator \(M\) on Lipschitz and Hölder functions in the context of homogeneous spaces. It is shown that in spaces satisfying a so-called annular decay property, \(M\) maps spaces of Hölder type to other spaces of Hölder type (the Hölder index is preserved if small enough).
openaire +2 more sources
Parametric Time‐Variation in the Unconditional Volatility: Estimation and Inference
Journal of Time Series Analysis, EarlyView.ABSTRACT We propose modeling time‐variation in the unconditional volatility by augmenting the standard GARCH model by a deterministic time‐varying intercept. The model, called the additive time‐varying (ATV‐)GARCH model, can be interpreted as a reduced form of a model including covariates and can be derived from a multiplicative decomposition of ...
Niklas Ahlgren +2 more
wiley +1 more source
Asymptotics of Time‐Varying Processes in Continuous‐Time Using Locally Stationary Approximations
Journal of Time Series Analysis, EarlyView.ABSTRACT We introduce a general theory on stationary approximations for locally stationary continuous‐time processes. Based on the stationary approximation, we use θ$$ \theta $$‐weak dependence to establish laws of large numbers and central limit type results under different observation schemes.
Robert Stelzer, Bennet Ströh
wiley +1 more source
Detecting Multiple Change Points in Linear Models With Heteroscedasticity
Journal of Time Series Analysis, EarlyView.ABSTRACT The problem of detecting change points in the parameters of a linear regression model with errors and covariates exhibiting heteroscedasticity is considered. Asymptotic results for weighted functionals of the cumulative sum (CUSUM) processes of model residuals are established when the model errors are weakly dependent and non‐stationary ...
Lajos Horváth +2 more
wiley +1 more source
Using wavelets for Szász-type operators
Journal of Numerical Analysis and Approximation Theory, 1995 Szász-Mirakjan operators extend the classical Bernstein operators and are useful tools for approximating continuous functions on the infinite interval \([0, \infty)\). These operators have integral variations of Kantorovich and Durrmeyer types in order
Heinz H. Gonska, Ding-Xuan Zhou
doaj +2 more sources
Partial Time‐Varying Regression Modelling Under General Heterogeneity
Journal of Time Series Analysis, EarlyView.ABSTRACT This paper studies a semiparametric time‐varying regression model in which a subset of regressors is associated with fixed parameters, while the remaining regressors have parameters that evolve smoothly over time. We propose a closed‐form semiparametric Frisch‐Waugh‐Lovell estimator for the fixed parameters, and a non‐parametric kernel type ...
Liudas Giraitis +3 more
wiley +1 more source
Measure‐valued processes for energy markets
Mathematical Finance, Volume 35, Issue 2, Page 520-566, April 2025.Abstract We introduce a framework that allows to employ (non‐negative) measure‐valued processes for energy market modeling, in particular for electricity and gas futures. Interpreting the process' spatial structure as time to maturity, we show how the Heath–Jarrow–Morton approach can be translated to this framework, thus guaranteeing arbitrage free ...
Christa Cuchiero +3 more
wiley +1 more source
Reinforcement Learning for Jump‐Diffusions, With Financial Applications
Mathematical Finance, EarlyView.ABSTRACT We study continuous‐time reinforcement learning (RL) for stochastic control in which system dynamics are governed by jump‐diffusion processes. We formulate an entropy‐regularized exploratory control problem with stochastic policies to capture the exploration–exploitation balance essential for RL.
Xuefeng Gao, Lingfei Li, Xun Yu Zhou
wiley +1 more source
Never, Ever Getting Started: On Prospect Theory Without Commitment
Mathematical Finance, EarlyView.ABSTRACT Prospect theory is arguably the most prominent alternative to expected utility theory. We study the investment or gambling behavior of a prospect theory decision maker who is aware of his time‐inconsistency but lacks commitment. For the empirically relevant prospect theory specifications, we obtain the extreme prediction that such a decision ...
Sebastian Ebert, Philipp Strack
wiley +1 more source
Relative Arbitrage Opportunities With Interactions Among N Investors
Mathematical Finance, EarlyView.ABSTRACT The relative arbitrage portfolio outperforms a benchmark portfolio over a given time‐horizon with probability one. With market price of risk processes depending on the market portfolio and investors, this paper analyzes the multi‐agent optimization of relative arbitrage opportunities in the coupled system of market and wealth dynamics.
Tomoyuki Ichiba, Nicole Tianjiao Yang
wiley +1 more source