Innovations, Rents and Risk

This research was conducted within the Paul Woolley Research Initiative on Capital Market Dysfunctionalities at IDEI, Toulouse. Support from the Europlace Institute of Finance is gratefully aknowledged. Many thanks to participants in the first conference of the Centre for the Study of Capital Market Dysfunctionality at the London School of Economics, the Pompeu Fabra Conference on the Financial Crisis, the third Banco de Portugal conference on Financial Intermediation, the Europlace Institute of Finance 7th Annual Forum, as well as seminar participants at London Business School, Frankfurt University, the European Central Bank and Amsterdam University, especially Sudipto Bhattacharya, Arnoud Boot, John Boyd, Markus Brunnermeier, Catherine Casamatta, Zvi Eckstein, Guido Friebel, Alex Gümbel, Philipp Hartmann, Augustin Landier, Thomas Mariotti, John Moore, Liliana Pellizzon, Enrico Perotti, Ludovic Phalippou, Guillaume Plantin and Steve Schaefer.

Free Cash-Flow, Issuance Costs and Stock Price Volatility

We study the issuance and payout policies that maximize the value of a firm facing both agency costs of free cash-flow and external financing costs. We find that the firm optimally issues equity. Equity distributes no dividends until a target cash level is reached, while new equity is issued when the firm runs out of cash. We characterize the process modelling the number of outstanding shares and the dynamics of the stock prices. In line with the leverage effect identified by Black (1976), we show that both the volatility of stock returns and the dollar volatility of stock prices increase after a negative shock on stock prices.

European Cyber Security System

Nowadays computer networks are widely spread in all spheres of human life. That is why the problem of cyber security of mankind is of great importance. Today, the European Union makes efforts to guarantee network safety in Europe by means of increase its member states in power and international cooperation in cyber security, including non-member countries, to prevent cyber crimes. Striving to join the European Union, Ukraine is involved in the process of providing cyber security. This paper examines the main strategies of EU standards in cyber security to be followed by Ukraine as one of European countries

Insights on the dynamical history of the Fomalhaut system - Investigating the Fom c hypothesis

The eccentric shape of the debris disk observed around Fomalhaut was first attributed to Fom b, a companion detected near the belt inner-edge, but new constraints on its orbit revealed that it is belt-crossing, highly eccentric $(e \sim 0.6-0.9)$, and can hardly account for the shape of the belt. The best scenario to explain this paradox is that there is another massive body in this system, Fom c, which drives the debris disk shape. The resulting planetary system is highly unstable, which hints at a dynamical scenario involving a recent scattering of Fom b on its current orbit, potentially with the putative Fom c. Our goal is to give insights on the probability for Fom b to have been set on its highly eccentric orbit by a close-encounter with the putative Fom c. We aim to study in particular the part played by mean-motion resonances with Fom c, which could have brought Fom b sufficiently close to Fom c for it to be scattered on its current orbit, but also delay this scattering event. Using N-body simulations, we found that the generation of orbits similar to that of Fom b, either in term of dimensions or orientation, is a robust process involving a scattering event and a further secular evolution of inner material with an eccentric massive body such as the putative Fom c. We found in particular that mean-motion resonances can delay scattering events, and thus the production of Fom b-like orbits, on timescales comparable to the age of the system, thus explaining the witnessing of an unstable configuration. We conclude that Fom b probably originated from an inner resonance with Fom c, which is at least Neptune-Saturn size, and was set on its current orbit by a scattering event with Fom c. Since Fom b could not have formed from material in resonance, our scenario also hints at former migration processes in this planetary system

The Continuous Skolem-Pisot Problem: On the Complexity of Reachability for Linear Ordinary Differential Equations

We study decidability and complexity questions related to a continuous analogue of the Skolem-Pisot problem concerning the zeros and nonnegativity of a linear recurrent sequence. In particular, we show that the continuous version of the nonnegativity problem is NP-hard in general and we show that the presence of a zero is decidable for several subcases, including instances of depth two or less, although the decidability in general is left open. The problems may also be stated as reachability problems related to real zeros of exponential polynomials or solutions to initial value problems of linear differential equations, which are interesting problems in their own right.Comment: 14 pages, no figur

Delphes stat

Également disponible en version papier.Titre de l'écran-titre (visionné le 20 janv. 2010)Vol.1 Guide théorique -- v.2 Guide pédagogique -- v.3 Guide technique