235 research outputs found
Sweeping the Space of Admissible Quark Mass Matrices
We propose a new and efficient method of reconstructing quark mass matrices
from their eigenvalues and a complete set of mixing observables. By a
combination of the principle of NNI (nearest neighbour interaction) bases which
are known to cover the general case, and of the polar decomposition theorem
that allows to convert arbitrary nonsingular matrices to triangular form, we
achieve a parameterization where the remaining freedom is reduced to one
complex parameter. While this parameter runs through the domain bounded by a
circle with radius R determined by the up-quark masses around the origin in the
complex plane one sweeps the space of all mass matrices compatible with the
given set of data.Comment: 18 page
Quantum field theory on a discrete space and noncommutative geometry
We analyse in detail the quantization of a simple noncommutative model of
spontaneous symmetry breaking in zero dimensions taking into account the
noncommutative setting seriously. The connection to the counting argument of
Feyman diagrams of the corresponding theory in four dimensions is worked out
explicitly. Special emphasis is put on the motivation as well as the
presentation of some well-known basic notions of quantum field theory which in
the zero-dimensional theory can be studied without being spoiled by technical
complications due to the absence of divergencies.Comment: 111 pages, 6 figures, Habilitationsschrif
Leptonic Generation Mixing, Noncommutative Geometry and Solar Neutrino Fluxes
Triangular mass matrices for neutrinos and their charged partners contain
full information on neutrino mixing in a most concise form. Although the scheme
is general and model independent, triangular matrices are typical for reducible
but indecomposable representations of graded Lie algebras which, in turn, are
characteristic for the standard model in noncommutative geometry. The mixing
matrix responsible for neutrino oscillations is worked out analytically for two
and three lepton families. The example of two families fixes the mixing angle
to just about what is required by the Mikheyev-Smirnov-Wolfenstein resonance
oscillation of solar neutrinos. In the case of three families we classify all
physically plausible choices for the neutrino mass matrix and derive
interesting bounds on some of the moduli of the mixing matrix.Comment: LaTeX, 12 page
Only Three
It is shown that it is possible to account for all experimental indications
for neutrino oscillations with just three flavours. In particular we suggest
that the atmospheric neutrino anomaly and the LSND result can be explained by
the same mass difference and mixing. Possible implications and future tests of
the resulting mass and mixing pattern are given.Comment: 10 pages, 2 Postscript figures (eps
Uncertainty Analysis for Data-Driven Chance-Constrained Optimization
In this contribution our developed framework for data-driven chance-constrained optimization is extended with an uncertainty analysis module. The module quantifies uncertainty in output variables of rigorous simulations. It chooses the most accurate parametric continuous probability distribution model, minimizing deviation between model and data. A constraint is added to favour less complex models with a minimal required quality regarding the fit. The bases of the module are over 100 probability distribution models provided in the Scipy package in Python, a rigorous case-study is conducted selecting the four most relevant models for the application at hand. The applicability and precision of the uncertainty analyser module is investigated for an impact factor calculation in life cycle impact assessment to quantify the uncertainty in the results. Furthermore, the extended framework is verified with data from a first principle process model of a chloralkali plant, demonstrating the increased precision of the uncertainty description of the output variables, resulting in 25% increase in accuracy in the chance-constraint calculation.BMWi, 0350013A, ChemEFlex - Umsetzbarkeitsanalyse zur Lastflexibilisierung elektrochemischer Verfahren in der Industrie; Teilvorhaben: Modellierung der Chlor-Alkali-Elektrolyse sowie anderer Prozesse und deren Bewertung hinsichtlich Wirtschaftlichkeit und möglicher HemmnisseDFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische UniversitÀt Berli
Allocation to social positions in class: interactions and relationships in first grade school classes and their consequences
"Using the approach of qualitative social network research, this article focuses on two âsystems of social inequalityâ on the basis of which learning is organized: one is the institutional and organizational framework structuring the encounters between teachers and students, the other is a system of social inequality incorporated at the level of emotions and affections. Both systems seem to be virtually inevitable and, due to the tacit nature of their workings in class interactions, escape attempts at deliberate control. The article demonstrates how the web of social relationships in the early grades acts to reinforce both systems of social inequality and how they mutually affect one another in the class setting. Two first grade classes were studied for this purpose using mixed methods. The findings clearly support these conclusions: in both classes under study, a configuration of relationships consisting of a range of distinct (student) positions has emerged, and all parties involved have a similar perception of this social configuration. These social positions, each of which offer different opportunities for learning, are reflected both in interactions (as evidenced by video analysis) and the studentsâ stories (as evidenced in interviews). Such stabilization processes determine student careers early on and render the class setting 'porous' as a space of learning." [author's abstract
Differential Algebras in Non-Commutative Geometry
We discuss the differential algebras used in Connes' approach to Yang-Mills
theories with spontaneous symmetry breaking. These differential algebras
generated by algebras of the form functions matrix are shown to be
skew tensorproducts of differential forms with a specific matrix algebra. For
that we derive a general formula for differential algebras based on tensor
products of algebras. The result is used to characterize differential algebras
which appear in models with one symmetry breaking scale.Comment: 21 page
Gravity, Non-Commutative Geometry and the Wodzicki Residue
We derive an action for gravity in the framework of non-commutative geometry
by using the Wodzicki residue. We prove that for a Dirac operator on an
dimensional compact Riemannian manifold with , even, the Wodzicki
residue Res is the integral of the second coefficient of the heat
kernel expansion of . We use this result to derive a gravity action for
commutative geometry which is the usual Einstein Hilbert action and we also
apply our results to a non-commutative extension which, is given by the tensor
product of the algebra of smooth functions on a manifold and a finite
dimensional matrix algebra. In this case we obtain gravity with a cosmological
constant.Comment: 17p., MZ-TH/93-3
Non-renormalization theorems of Supersymmetric QED in the Wess-Zumino gauge
The non-renormalization theorem of chiral vertices and the generalized
non-renormalization theorem of the photon self energy are derived in SQED on
the basis of algebraic renormalization. For this purpose the gauge coupling is
extended to an external superfield. This extension already provides detailed
insight into the divergence structure. Moreover, using the local supercoupling
together with an additional external vector multiplet that couples to the axial
current, the model becomes complete in the sense of multiplicative
renormalization, with two important implications. First, a Slavnov--Taylor
identity describing supersymmetry, gauge symmetry, and axial symmetry including
the axial anomaly can be established to all orders. Second, from this
Slavnov-Taylor identity we can infer a Callan-Symanzik equation expressing all
aspects of the non-renormalization theorems. In particular, the gauge
-function appears explicitely in the closed form.Comment: Latex, 47 page
Zum Design(begriff) der Netzwerkgesellschaft: Design als zentrales Element der IdentitÀtsformation in Netzwerken
Der Verfasser setzt sich zunĂ€chst mit Dirk Baeckers Begriff der 'next society' auseinander, der damit entgegen der Mainstream-Soziologie Design-Elemente zur Anwendung bringt. Vor diesem Hintergrund wird das eigene rationale Designkonzept vorgestellt, das einen Designbegriff auf Basis einer zunĂ€chst vorgenommenen Konzentration auf DesignphĂ€nomene im engeren Sinn gewinnt, also auf Gestaltungsprozesse von Designern. Besonderes Augenmerk wird dabei darauf gelegt, dass dieser Designbegriff auch als eine gangbare Alternative zum Ăbersetzungsbegriff der Akteur-Netzwerk-Theorie fungiert. Design trĂ€gt nicht nur zur IdentitĂ€tsbildung von Akteuren bei, sondern auch zur Konstituierung ganzer Milieus und Kulturen. Insofern vermittelt der Designbegriff zwischen sozialen Mikro- und MakrophĂ€nomenen. AbschlieĂend wird ein ausgeweitetes Designkonzept vorgeschlagen, das alle gestalterischen Aspekte der IdentitĂ€tsformation erfassen soll, die sich in sozialen Netzwerken beobachten lassen. Den Transmissionsriemen dafĂŒr stellt eine aktuelle Debatte einer Ausweitung des BetĂ€tigungsfeldes der Designer dar, die bereits weit ĂŒber die Designprofession hinaus wirkt, die Debatte ĂŒber 'design thinking'. Design thinking kann als die Grammatik viel versprechender Kontrollprojekte in der 'next society' aufgefasst werden. (ICE2
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