Results 31 to 40 of about 2,001,462 (190)

Two-parameter diffusion processes and martingales

open access: yesStochastic Processes and their Applications, 1983
AbstractWe introduce a class of two-parameter processes which are diffusions on each coordinate and satisfy a particular Markov property related to the partial ordering in R2+. These processes can be expressed as solutions of some stochastic integral equations driven by a two-parameter Wiener process and two families of ordinary Brownian motions.
openaire   +2 more sources

Empirical‐Process Limit Theory and Filter Approximation Bounds for Score‐Driven Time Series Models

open access: yesJournal of Time Series Analysis, EarlyView.
ABSTRACT This article examines the filtering and approximation‐theoretic properties of score‐driven time series models. Under specific Lipschitz‐type and tail conditions, new results are derived, leading to maximal and deviation inequalities for the filtering approximation error using empirical process theory.
Enzo D'Innocenzo
wiley   +1 more source

Estimation of the Intercept Parameter in Integrated Galton–Watson Processes

open access: yesJournal of Time Series Analysis, EarlyView.
ABSTRACT We study the estimation of the intercept parameter in an integrated Galton–Watson process, an important building block for many count‐valued time series models. In this unit root setting, the ordinary least squares estimator is known to be inconsistent, whereas the existing weighted least squares (WLS) estimator is consistent only in the case ...
Yang Lu
wiley   +1 more source

Testing for Rough Volatility When Prices Are Purely Discontinuous

open access: yesJournal of Time Series Analysis, EarlyView.
ABSTRACT We consider the problem of nonparametric testing for rough volatility, using high‐frequency data with a fixed time span, in a setting where the price is purely discontinuous. More specifically, we analyze the asymptotic properties of a test we developed in previous work in a pure‐jump setting.
Carsten H. Chong, Viktor Todorov
wiley   +1 more source

On Testing for Independence Between Generalized Error Models of Several Time Series

open access: yesJournal of Time Series Analysis, EarlyView.
ABSTRACT We define generalized innovations associated with generalized error models having arbitrary distributions, that is, distributions that can be mixtures of continuous and discrete distributions. These models include stochastic volatility models and regime‐switching models with possibly zero‐inflated regimes.
Kilani Ghoudi   +2 more
wiley   +1 more source

Penalized Convex Estimation in Dynamic Location Models

open access: yesJournal of Time Series Analysis, EarlyView.
ABSTRACT This paper studies L1$$ {L}^1 $$‐penalized estimation for location models yt=mt+ϵt$$ {y}_t={m}_t+{\epsilon}_t $$, where mt$$ {m}_t $$ is defined by a possibly non‐Markovian recursion and ϵt$$ {\epsilon}_t $$ is a martingale difference sequence with possibly time‐varying conditional variance.
Reda Alami Chentoufi
wiley   +1 more source

Detecting Periodicity of a General Stationary Time Series via AR(2)‐Model Fitting

open access: yesJournal of Time Series Analysis, EarlyView.
ABSTRACT Estimating the periodicity of a stationary time series via fitting a second‐order stationary autoregressive (AR(2)) model has been initiated by the seminal paper of Yule (1927). We investigate properties of this procedure when applied to general stationary processes possessing a spectral density with a dominant peak at some unknown frequency ...
Jens‐Peter Kreiss   +2 more
wiley   +1 more source

Measure‐valued processes for energy markets

open access: yesMathematical 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

Optimal Portfolio Choice With Cross‐Impact Propagators

open access: yesMathematical Finance, EarlyView.
ABSTRACT We consider a class of optimal portfolio choice problems in continuous time where the agent's transactions create both transient cross‐impact driven by a matrix‐valued Volterra propagator, as well as temporary price impact. We formulate this problem as the maximization of a revenue‐risk functional, where the agent also exploits available ...
Eduardo Abi Jaber   +2 more
wiley   +1 more source

On Changing Time for Two-Parameter Strong Martingales: A Counterexample

open access: yesThe Annals of Probability, 1986
Brownian motion owes part of its significance to the fact that any continuous martingale may be considered as a Brownian motion running with a different clock. This means that by a suitable time change any continuous martingale can be transformed into Brownian motion.
openaire   +3 more sources

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