Showing papers by "Agus Purwanto published in 2009"

Cosmological evolution of interacting dark energy in Lorentz violation

Abstract: The cosmological evolution of an interacting scalar-field model in which the scalar field interacts with dark matter, radiation, and baryons via Lorentz violation is investigated. We propose a model of interaction through the effective coupling, $\bar{\beta}$ . Using dynamical system analysis, we study the linear dynamics of an interacting model and show that the dynamics of critical points are completely controlled by two parameters. Some results can be mentioned as follows. Firstly, the sequence of radiation, the dark matter, and the scalar-field dark energy exist and baryons are subdominant. Secondly, the model also allows for the possibility of having a universe in the phantom phase with constant potential. Thirdly, the effective gravitational constant varies with respect to time through $\bar{\beta}$ . In particular, we consider the simple case where $\bar{\beta}$ has a quadratic form and has a good agreement with the modified ΛCDM and quintessence models. Finally, we also calculate the first post-Newtonian parameters for our model.

Karakteristik perusahaan, praktik corporate governance, keputusan keuangan, perataan laba dan nilai perusahaan

Abstract: This is aimed to investigate the influence of companies characteristics and corporate govern-ance on income smoothing: and the influence of corporate governance and financial decisions on companies value and on public companies listed on Indonesian Stock Exchange (IDX). Moreover, this study is intended to analyse the causality relationship between income smooth¬ing and firm value of the public companies listed at the Indonesian Stock Exchange IDX). This research used samples of 56 public companies listed on Indonesian Stock Exchange (IDX) for the periods of 2000 to 2005, Data were then analysed using simultaneous-equation model involving two-stage least square method. The results of this research showed that type of industry influenced income smoothing while the others companies characteristics variables and corporate governance practice variables do not influence income smoothing. In addi¬tion, investment decision influenced firm value whreas others financial decisions variables and corporate governance practice do not influence firm value. Finally there is no causality relation between income smoothing with firm value. Keywords: earning management, income smoothing, corporate governance, net profit margin, operating profit margin