21,278 research outputs found
Recent Conceptual Consequences of Loop Quantum Gravity. Part I: Foundational Aspects
Conceptual consequences of recent results in loop quantum gravity are
collected and discussed here in view of their implications for a modern
philosophy of science which is mainly understood as one that totalizes
scientific insight so as to eventually achieve a consistent model of what may
be called fundamental heuristics on an onto-epistemic background which is part
of recently proposed transcendental materialism. This enterprise is being
understood as a serious attempt of answering recent appeals to philosophy so as
to provide a conceptual foundation for what is going on in modern physics, and
of bridging the obvious gap between physics and philosophy. This present first
part of the paper deals with foundational aspects of this enterprise, a second
part will deal with its holistic aspects.Comment: 25 page
Loops and Knots as Topoi of Substance. Spinoza Revisited
The relationship between modern philosophy and physics is discussed. It is
shown that the latter develops some need for a modernized metaphysics which
shows up as an ultima philosophia of considerable heuristic value, rather than
as the prima philosophia in the Aristotelian sense as it had been intended, in
the first place. It is shown then, that it is the philosophy of Spinoza in
fact, that can still serve as a paradigm for such an approach. In particular,
Spinoza's concept of infinite substance is compared with the philosophical
implications of the foundational aspects of modern physical theory. Various
connotations of sub-stance are discussed within pre-geometric theories,
especially with a view to the role of spin networks within quantum gravity. It
is found to be useful to intro-duce a separation into physics then, so as to
differ between foundational and empirical theories, respectively. This leads to
a straightforward connection bet-ween foundational theories and speculative
philosophy on the one hand, and between empirical theories and sceptical
philosophy on the other. This might help in the end, to clarify some recent
problems, such as the absence of time and causality at a fundamental level. It
is implied that recent results relating to topos theory might open the way
towards eventually deriving logic from physics, and also towards a possible
transition from logic to hermeneutic.Comment: 42 page
Recent Conceptual Consequences of Loop Quantum Gravity. Part II: Holistic Aspects
Based on the foundational aspects which have been discussed as consequences
of ongoing research on loop quantum gravity in the first part of this paper,
the holistic aspects of the latter are discussed in this second part, aiming at
a consistent and systematic approach to eventually model a hierarchically
ordered architecture of the world which is encompassing all of what there
actually is. The idea is to clarify the explicit relationship between physics
and philosophy on the one hand, and philosophy and the sciences in general, on
the other. It is shown that the ontological determination of worldliness is
practically identical with its epistemological determination so that the
(scientific) activity of modelling and representing the world can be visualized
itself as a (worldly) mode of being.Comment: 20 page
Comment on "Dephasing Times in Quantum Dots due to Elastic LO Phonon-Carrier Collisions"
This paper is a Comment on Phys. Rev. Lett. 85, 1516 (2000) by A.V. Uskov,
A.-P. Jauho, B. Tromborg, J. Mork, and R. Lang.Comment: 1 page, 1 figure. Phys. Rev. Lett., accepte
Topography of Generically Folded Spacecapes: Towards a Cognitive Metatheory in Architectural Design
If we visualize philosophy as a science of the sciences (in the tradition of Hans Heinz Holz), then theories within the philosophical framework are always meta-theories of the respective field of interest in question with which philosophy is actually dealing. Hence, a philosophy of architecture in particular, shows up as a meta-theory of theories of architecture with respect to all the possible conditions that are necessary to actually constitute its characteristic field of interest (including the social modes of communication). As we can easily see, it is also a cognitive meta-theory in the first place (i.e. one of the human condition). If then, traditionally, philosophy can also be visualized as being primarily constituted by four components that turn to its topic, namely by means of historical analysis, scientific approach, aesthetical and
ethical conceptualizations, respectively, we can recognize that the second and the third overlap somehow with the architectural activities. This is certainly true since the establishment of architecture as a field of activity of its own, separated from building and engineering, as was achieved in the epoch of the Italian Renaissance by Brunelleschi, Alberti, and others.Peer Reviewe
Near-field spectra of quantum well excitons with non-Markovian phonon scattering
The excitonic absorption spectrum for a disordered quantum well in presence
of exciton-acoustic phonon interaction is treated beyond the Markov
approximation. Realistic disorder exciton states are taken from a microscopic
simulation, and the deformation potential interaction is implemented. The
exciton Green's function is solved with a self energy in second order Born
quality. The calculated spectra differ from a superposition of Lorentzian
lineshapes by enhanced inter-peak absorption. This is a manifestation of pure
dephasing which should be possible to measure in near-field experiments.Comment: 8 pages, 7 figure
Modeling microwave/electron-cloud interaction
Starting from the separate codes BI-RME and ECLOUD or PyECLOUD, we are
developing a novel joint simulation tool, which models the combined effect of a
charged particle beam and of microwaves on an electron cloud. Possible
applications include the degradation of microwave transmission in
tele-communication satellites by electron clouds; the microwave-transmission
tecchniques being used in particle accelerators for the purpose of
electroncloud diagnostics; the microwave emission by the electron cloud itself
in the presence of a magnetic field; and the possible suppression of
electron-cloud formation in an accelerator by injecting microwaves of suitable
amplitude and frequency. A few early simulation results are presented.Comment: 3 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop
on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba,
Ital
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