Matter of Life & Death: The impact of environmental conditions on the origins of stars and supermassive black holes

Observational evidence suggests that some very large supermassive black holes (SMBHs) already existed less than 1 Gyr after the Big Bang. Explaining the formation and growth of the 'seeds' of these SMBHs is quite challenging. We explore the formation of such seeds in the direct collapse scenario. Using 3D hydrodynamical simulations, we investigate the impact of turbulence and rotation on the fragmentation behavior of collapsing primordial gas in the presence of a strong UV radiation background, which keeps the gas hot. Additionally, we explore different ways in which the collapsing gas may be able to stay hot, and thus limit fragmentation. Using a one-zone model, we examine the interplay between magnetic fields, turbulence, and a UV radiation background. Feedback processes from stars and black holes shape the interstellar medium (ISM) out of which new generations of luminous objects form. To understand the properties of these objects, e.g. the stellar initial mass function, it is vital to have knowledge of the chemical and thermodynamical properties of the feedback-regulated ISM. To better understand the chemo-thermal state and fragmentation behavior of gas in high-redshift galaxies, we updated, improved, and extended a photodissociation region code. Our computational code, PDR-Zz, is described in detail. Using this code, a grid of models is run, covering a sizable range in physical properties. This allows us to systematically explore the overall impact of various feedback effects, both radiative and chemical, on the chemical and thermal balance of the gas in different physical regimes.Comment: 268 pages, PhD thesis, University of Groningen & Georg-August Universit\"at G\"ottingen. For a higher quality version, see http://www.astro.rug.nl/~borm/cvanborm_phdthesis_web_hq.pdf (23MB

A New Relative Skill Measure for Games with Chance Elements

An interesting aspect of games is the relative extent to which a player can positively influence his results by making appropriate strategic choices. This question is closely related to the issue of how to distinguish between games of skill and games of chance. The distinction between these two types of games is definitely interesting from a juridical point of view. Borm and Van der Genugten (2001) presented a method to measure the skill level of a game. In principle, their measure can serve as a juridical tool for the classification of games with respect to skill. In this paper we present a modification of the measure. The main difference is that this new definition does not automatically classify incomplete information games without chance moves as games of skill. We use a coin game and a simplified version of standard drawpoker as an illustration.games of skill;games of chance

On Strategy and Relative Skill in Poker

This article presents a generalization of the equilibrium analysis for the simple two-player poker game with alternate bidding of Von Neumann and Morgenstern.It approximates optimal play for this game if it is played with a regular deck of 52 cards and it discusses some strategic insights.In addition, the paper studies the relative skill level of this game.game theory

Economic lot-sizing games

In this paper we introduce a new class of OR games: economic lot-sizing (ELS) games.There are a number of retailers that have a known demand for a fixed number of periods.To satisfy demand the retailers order products at the same manufacturer. By placing jointorders instead of individual orders, costs can be reduced and a cooperative game arises. In this paper we show that ELS games are balanced. Furthermore, we show that two specialclasses of ELS games are concave.Game Theory;Lot-sizing;Inventory;Production