In this study the nature of transition to metallic regime in trans-polyacetylene (trans-PA) is investigated. Based on Su-Schrieffer-Heeger (SSH) model and the use of Continued - Fraction Representation (CFR) as well as Lanczos algorithm procedure, we studied the effects of some selected soliton distributions on the semiconductor-to-metal transition in trans-PA.We found that,this transition occ...

The business cycles are one of the most important economic indicators that they show the changes in economic activities during time. The study of business cycles is important because the understanding fluctuations in GDP and effective factors on these fluctuations help policy makers to plan better and more efficient. The main purpose of this paper is to investigate the effects of oil price shoc...

The economy of Iran has witnessed a couple of booms and busts in housing prices over the period of 1981(1)-2014(4). Since the fluctuations in housing prices affect household wealth, and consequentially, total consumption, saving and even banking, it is of crucial importance to analyze the impact of such fluctuations on real economy. This study, utilizing the MSIAH -VARX model, examines booms an...

Unemployment is one of the most important challenges of Iran’s economy which affects on society and economic performance. The purpose of this paper is examining the effect of exchange rate gap (difference between official and parallel market rates) on unemployment rate in Iran during 1974-2012 based on Markov-Switching model. The empirical results indicate that, in high unemployment regime, exc...

Recently instability in Iranian exchange market, particularly after imposing huge economic sanctions has generated a lot interest among economist and academicians to investigate driving force of this instability. This paper estimates a new nonlinear exchange market pressure for Iran’s economy using MSMH(2)-VAR(2) method. The empirical results identify the two episodes of exchange market pr...