Department of Mathematics and Statistics
Work by the faculty and students of the Department of Mathematics and Statistics
Recent Submissions

The Beverton–Holt model with periodic and conditional harvesting
(Taylor & Francis Online, 2009)In this theoretical study, we investigate the effect of different harvesting strategies on the discrete Beverton–Holt model in a deterministic environment. In particular, we make a comparison between the constant, periodic ... 
Basin of Attraction through Invariant Curves and Dominant Functions
(Hindawi, 2015)We study a secondorder difference equation of the form 𝑧ₙ₊₁= 𝑧ₙ𝐹(𝑧ₙ₋₁) + ℎ, where both 𝐹(𝑧) and 𝑧𝐹(𝑧) are decreasing. We consider a set of invariant curves at ℎ = 1 and use it to characterize the behaviour of ... 
The Discrete BevertonHolt Model with Periodic Harvesting in a Periodically Fluctuating Environment
(Springer, 2010)We investigate the effect of constant and periodic harvesting on the BevertonHolt model in a periodically fluctuating environment. We show that in a periodically fluctuating environment, periodic harvesting gives a better ... 
A Global Attractor in Some Discrete Contest Competition Models with Delay under the Effect of Periodic Stocking
(Hindawi, 2013)We consider discrete models of the form 𝒳ₙ₊₁= 𝒳ₙ𝒇(𝒳ₙ₋₁) + 𝒉ₙ , where 𝒉ₙ is a nonnegative 𝒑periodic sequence representing stocking in the population, and investigate their dynamics. Under certain conditions on the ... 
Martingale problem for superprocesses with nonclassical branching functional
(Elsevier, 2006)The martingale problem for superprocesses with parameters (𝛏, Ф, 𝑘) is studied where 𝑘(𝒹𝑠) may not be absolutely continuous with respect to the Lebesgue measure. This requires a generalization of the concept of ... 
Market Efficiency of Floating Exchange Rate Systems: Some Evidence from PacificAsian Countries
(Elsevier, 2011)This paper examines the random walk hypothesis (RWH) and the martingale difference hypothesis (MDH) for the Australian dollar and five Asian emerging currencies relative to three benchmark currencies. We use Wright’s (2000) ... 
Exercisability Randomization of the American Option
(Taylor & Frances Online, 2008)The valuation of American options is an optimal stopping time problem which typically leads to a free boundary problem. We introduce here the randomization of the exercisability of the option. This method considerably ... 
Convergence rate of the binomial tree scheme for continuously paying options
(Université du Québec à Montréal, 2012)Continuously Paying Options (CPOs) form a very natural class of derivatives for hedging risks coming from adverse movements of a continuously traded asset. We study the rate of convergence of CPOs evaluated under the ... 
A European option general firstorder error formula
(Cambridge, 2013)We study the value of European security derivatives in the BlackScholes model, when the underlying asset 𝛏 is approximated by random walks 𝛏(𝑛). We obtain an explicit error formula, up to a term of order 𝒪(𝑛⁻³/² ), ... 
Can HighOrder Convergence of European Option Prices be Achieved with Common CRRType Binomial Trees?
(Springer, 2015)Considering European call options, we prove that CRRtype binomial trees systematically underprice the value of these options, when the spot price is not near the money. However, we show that, with a volatility premium to ... 
Option convergence rate with geometric random walks approximations
(Taylor & Frances Online, 2016)We describe a broad setting under which, for European options, if the underlying asset form a geometric random walk then, the error with respect to the Black–Scholes model converges to zero at a speed of 1/𝑛 for continuous ... 
A Market Efficiency Comparison of Islamic and NonIslamic Stock Indices
(Taylor & Francis Online, 2015)This article examines the martingale difference hypothesis (MDH) and the random walk hypothesis (RWH) for nine conventional and nine Islamic stock indices: AsiaPacific, Canadian, Developed Country, Emerging, European, ... 
A robust method to retrieve option implied risk neutral densities for defaultable assets
(Inderscience Publishers, 2016)Risk neutral densities recovered from option prices can be used to infer market participants' expectations of future stock returns and are a vital tool for pricing illiquid exotic options. Although there is a broad literature ... 
Path Independence of Exotic Options and Convergence of Binomial Approximations
(Infopro Digital Risk (IP), 2019)The analysis of the convergence of tree methods for pricing barrier and lookback options has been the subject of numerous publications aiming at describing, quantifying, and improving the slow and oscillatory convergence ... 
Convergence rate of regimeswitching trees
(Elseveir, 2016)Considering a general class of regimeswitching geometric random walks and a broad class of piecewise twice differentiable payoff functions, we show that convergence of option prices occurs at a speed of order 𝒪 (𝑛ᵝ), ... 
Mechanical perturbation control of cardiac alternans
(American Physical Society, 2018)Cardiac alternans is a disturbance in heart rhythm that is linked to the onset of lethal cardiac arrhythmias. Mechanical perturbation control has been recently used to suppress alternans in cardiac tissue of relevant size. ... 
Control of cardiac alternans by mechanical and electrical feedback
(American Physical Society, 2014)A persistent alternation in the cardiac action potential duration has been linked to the onset of ventricular arrhythmia, which may lead to sudden cardiac death. A coupling between these cardiac alternans and the intracellular ... 
Modeling and simulation of hypothermia effects on cardiac electrical dynamics
(Public Library of Science, 3019)Previous experimental evidence has shown the effect of temperature on the action potential duration (APD). It has also been demonstrated that regional cooling of the heart can prolong the APD and promote the termination ... 
On weakly 2absorbing ideals of commutative rings
(University of Houston, 2013)Let R be a commutative ring with identity 1 not equal to 0. In this paper, we introduce the concept of a weakly 2absorbing ideal. A proper ideal I of R is called a weakly 2absorbing ideal of R if whenever abc is not equal ...