In this monograph we apply scattering theory methods to calculations in quantum ?eld theory, with a particular focus on properties of the quantum vacuum. These methods will provide e?cient and reliable solutions to a - riety of problems in quantum ?eld theory. Our approach will also elucidate in a concrete context many of the subtleties of quantum ?eld theory, such as divergences, regularization, and renormalization, by connecting them to more familiar results in quantum mechanics. We will use tools of scattering theory to characterize the spectrum of energyeigenstatesinapotentialbackground, hencethetermspectralmethods. This mode spectrum comprises both discrete bound states and a continuum of scattering states. We develop a powerful formalism that parameterizes the e?ects of the continuum by the density of states, which we compute from scattering data. Summing the zero-point energies of these modes gives the energy of the quantum vacuum, which is one of the central quantities we study.Althoughthemostcommonlystudiedbackgroundpotentialsarisefrom static soliton solutions to the classical equations of motion, these methods are not limited to such cases

In this monograph we apply scattering theory methods to calculations in quantum ?eld theory, with a particular focus on properties of the quantum vacuum. These methods will provide e?cient and reliable solutions to a - riety of problems in quantum ?eld theory. Our approach will also elucidate in a concrete context many of the subtleties of quantum ?eld theory, such as divergences, regularization, and renormalization, by connecting them to more familiar results in quantum mechanics. We will use tools of scattering theory to characterize the spectrum of energyeigenstatesinapotentialbackground, hencethetermspectralmethods. This mode spectrum comprises both discrete bound states and a continuum of scattering states. We develop a powerful formalism that parameterizes the e?ects of the continuum by the density of states, which we compute from scattering data. Summing the zero-point energies of these modes gives the energy of the quantum vacuum, which is one of the central quantities we study.Althoughthemostcommonlystudiedbackgroundpotentialsarisefrom static soliton solutions to the classical equations of motion, these methods are not limited to such cases

In den Wochen vor der Bundestagswahl 2002 deutete alles auf einen Regierungswechsel hin. Gleichwohl wurde die rot-grune Bundesregierung unter Gerhard Schroeder am 22. September 2002 knapp im Amt bestatigt. Dieser Last-Minute-Swing wird im Zusammenhang mit langfristigen Veranderungstrends des Wahlerverhaltens als das Ergebnis einer zunehmenden Individualisierung der Wahlentscheidung gedeutet. Kurzfristige Einflussfaktoren gewinnen demnach gegenuber den langfristigen Pragekraften der Wahlentscheidung an Bedeutung. Professionelle Wahlkampffuhrung und ein geschicktes Themenmanagement werden zu wichtigen Voraussetzungen des Wahlerfolgs. Vor diesem allgemeinen Hintergrund wird aufgezeigt, welche Rolle der drohende Krieg im Irak, die Flutkatastrophe und die TV-Duelle von Gerhard Schroeder und Edmund Stoiber fur die Wahlentscheidung bei der Bundestagswahl 2002 gespielt haben.