Analysis and control of transient spectra using time-dependent density functional theory.

215 p.Attosecond-transient absorption spectroscopy and attosecond time-resolved photoelectronspectroscopy based on pump-probe setups have recently become possibledue to the availability of ultra-fast pulsed laser sources. These experiments allow tofollow the electronic motion on its natural time-scale, allowing the characterizationof electronic excited states and transitions while neglecting the influence of thenuclear degrees of freedom. Molecular absorption and photo-electron spectra can beefficiently predicted with real-time time-dependent density-functional theory, whichis normally used for the description of systems in their ground state. In this thesis, Ishow how these techniques can be extended to study time-resolved pump-probeexperiments in an excited state providing a tool for the interpretation of fastevolving attosecond time-resolved spectroscopic experiments. I show how the extradegrees of freedom (pump pulse duration, intensity, frequency, and time-delay),which are absent in a conventional steady state experiment, provide additionalinformation about the electronic structure and the dynamics, which can be used toimprove a system characterization. As an extension of this approach, timedependent2D spectroscopies can also be simulated, in principle, for large-scalestructures and extended systems. In addition to numerical modelling, a theoreticalunderstanding of the processes would be useful. In this thesis, I reexamine theLehmann representation of the response function of a pump-driven system in thenon-overlapping regime, deriving some general properties of the excited statespectra, including position and shape of their resonance peaks. I demonstrate, howas a consequence, this Lehmann representation can be used to understand laserinducedline shape changes. Measurement and control of ultrafast processes areinherently intertwined. In this work, I assess the possibility of using tailored pumpsin order to enhance (or reduce) some given features of the probe absorption (forexample, absorption in the visible range of otherwise transparent samples). Thistype of manipulation of the system response could be helpful for its fullcharacterization, since it would allow to visualize transitions that are obscured whenusing un-shaped pulses. In order to investigate this possibility, I firstly combine theLehmann representation with a simple numerical model of the Hydrogen atom toshow, how Hydrogen can be manipulated to loose its transparency in the visible. Ithen proceed to investigate the feasibility of using time-dependent densityfunctionaltheory as a means to implement, theoretically, this absorptionoptimizationidea, for more complex atoms or molecules

Content and action: The guidance theory of representation

The current essay introduces the guidance theory of representation, according to which the content and intentionality of representations can be accounted for in terms of the way they provide guidance for action. We offer a brief account of the biological origins of representation, a formal characterization of the guidance theory, some examples of its use, and show how the guidance theory handles some traditional problem cases for representation: the problems of error and of representation of fictional and abstract entities

Levels of abstraction in human supervisory control teams

This paper aims to report a study into the levels of abstraction hierarchy (LOAH) in two energy distribution teams. The original proposition for the LOAH was that it depicted five levels of system representation, working from functional purpose through to physical form to determine causes of a malfunction, or from physical form to functional purpose to determine the purpose of system function. The LOAH has been widely used throughout human supervisory control research to explain individual behaviour. The research seeks to focus on the application the LOAH to human supervisory control teams in semi-automated “intelligent” systems

The *subjectivity* of subjective experience - A representationalist analysis of the first-person perspective

This is a brief and accessible English summary of the "Self-model Theory of Subjectivity" (SMT), which is only available as German book in this archive. It introduces two new theoretical entities, the "phenomenal self-model" (PSM) and the "phenomenal model of the intentionality-relation" PMIR. A representationalist analysis of the phenomenal first-person persepctive is offered. This is a revised version, including two pictures

Localization and Pattern Formation in Quantum Physics. I. Phenomena of Localization

In these two related parts we present a set of methods, analytical and numerical, which can illuminate the behaviour of quantum system, especially in the complex systems. The key points demonstrating advantages of this approach are: (i) effects of localization of possible quantum states, more proper than "gaussian-like states"; (ii) effects of non-perturbative multiscales which cannot be calculated by means of perturbation approaches; (iii) effects of formation of complex quantum patterns from localized modes or classification and possible control of the full zoo of quantum states, including (meta) stable localized patterns (waveletons). We'll consider calculations of Wigner functions as the solution of Wigner-Moyal-von Neumann equation(s) corresponding to polynomial Hamiltonians. Modeling demonstrates the appearance of (meta) stable patterns generated by high-localized (coherent) structures or entangled/chaotic behaviour. We can control the type of behaviour on the level of reduced algebraical variational system. At the end we presented the qualitative definition of the Quantum Objects in comparison with their Classical Counterparts, which natural domain of definition is the category of multiscale/multiresolution decompositions according to the action of internal/hidden symmetry of the proper realization of scales of functional spaces. It gives rational natural explanation of such pure quantum effects as ``self-interaction''(self-interference) and instantaneous quantum interaction.Comment: LaTeX2e, spie.cls, 13 pages, 15 figures, submitted to Proc. of SPIE Meeting, The Nature of Light: What is a Photon? Optics & Photonics, SP200, San Diego, CA, July-August, 200