366 research outputs found
Max Bense: Werk-Wirkung-Kontext
No full textMax Bense (1910–1990) gilt als Vorreiter der Computerkunst und der Technikphilosophie und war ein engagierter Förderer von Kunst und Literatur, Promotor interdisziplinären Denkens und politischer Provokateur. Häufig ist es bei der Auseinandersetzung mit Bense jedoch bei diesen Etikettierungen geblieben. Der Sammelband nimmt daher eine konzertierte Neuaufnahme der Diskussion von Max Benses Arbeiten aus literaturwissenschaftlicher, philosophie- und wissenschaftshistorischer sowie aus medien- und ästhetiktheoretischer Perspektive vor. Er versammelt Beiträge zu Themenkomplexen wie der Semiotik, Technikphilosophie, experimentellen Poesie und Ästhetiktheorie, zu Benses lokalen und internationalen Kontakten und Netzwerken sowie zu seinem publizistischen Verhalten im Nationalsozialismus und in der Nachkriegszeit
Dynamic structure factor and excitation spectrum of the one‐component plasma: The case of weak to moderate magnetization
No full textMagnetized plasmas are well known to exhibit a rich spectrum of collective modes. Here, we focus on the density modes in dense or cold plasmas, where strong coupling effects alter the mode spectrum known from traditional weakly coupled plasmas. In particular, we study the dynamic structure factor (DSF) of the magnetized one-component plasma with molecular dynamics simulations. Extending our previous results (H. Kählert and M. Bonitz, Phys. Rev. Research 2022, 4, 013197), it is shown that Bernstein modes can be observed in the weakly magnetized regime, where they are found below the upper hybrid frequency, provided the coupling strength is sufficiently low. We investigate the DSF for a variety of different wave numbers and plasma parameters and show that even small magnetization can give rise to a strong zero-frequency mode perpendicular to the magnetic field and change the dispersion as well as the damping of the upper hybrid mode
Remembering Manfred Bonitz (7.3.1931 - 14.8.2012) on the first anniversary of his death.
No full textLöwdin's symmetry dilemma within Green functions theory for the one-dimensional Hubbard model
No full textThe energy gap of correlated Hubbard clusters is well studied for one-dimensional systems using analytical methods and density-matrix-renormalization-group (DMRG) simulations. Beyond 1D, however, exact results are available only for small systems by quantum Monte Carlo. For this reason and, due to the problems of DMRG in simulating 2D and 3D systems, alternative methods such as Green functions combined with many-body approximations (GFMBA), that do not have this restriction, are highly important. However, it has remained open whether the approximate character of GFMBA simulations prevents the computation of the Hubbard gap. Here we present new GFMBA results that demonstrate that GFMBA simulations are capable of producing reliable data for the gap which agrees well with the DMRG benchmarks in 1D. An interesting observation is that the accuracy of the gap can be significantly increased when the simulations give up certain symmetry restriction of the exact system, such as spin symmetry and spatial homogeneity. This is seen as manifestation and generalization of the “symmetry dilemma” introduced by Löwdin for Hartree–Fock wave function calculations
"Geist ist wesentlich Form." Benses Stilbegriffe
No full textThe concept of style in its relation to thinking and writing undoubtedly plays a central role in Bense's philosophy. Throughout his life, however, he represented very different notions of style, rather conventional ones and others of disconcerting idiosyncrasy. In this essay, the transformations of the concept of style in Bense will be presented in an overview loosely oriented to chronology, and the argumentative contexts for the respective modifications will be outlined and assessed.Der Stilbegriff in seinem Verhältnis zum Denken und Schreiben spielt zweifellos eine zentrale Rolle in Benses Philosophie. Zeit seines Lebens vertrat er jedoch sehr unterschiedliche Stilbegriffe, eher konventionelle und andere von befremdlicher Eigentümlichkeit. In diesem Essay sollen die Wandlungen des Stilbegriffs bei Bense in einem locker an der Chronologie orientierten Überblick vorgeführt und die argumentativen Kontexte für die jeweiligen Modifikationen skizziert und beurteilt werden
On the Correct Reading of Metaphysics V 7, 1017a 34–35. The Logic Behind Aristotle’s Example of the Diagonal
No full textThis paper aims to clarify the opposition between Alexander of Aphrodisias, followed by Hermann Bonitz on one side, and Thomas Aquinas, followed by Lambertus Marie de Rijk on the other, regarding the correct reading of an example proposed by Aristotle in Metaphysics V 7, 1017a 34–35, which involves the diagonal and its incommensurability with the side. The author aims to demonstrate that Aquinas’s interpretation (and De Rijk’s one) cannot be accepted and that we should follow Alexander of Aphrodisias and Bonitz
Static properties of a warm dense uniform electron gas
No full textCopyright 2021 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Ara, Ll. Coloma, and I. M. Tkachenko , "Static properties of a warm dense uniform electron gas", Physics of Plasmas 28, 112704 (2021) https://doi.org/10.1063/5.0062259[EN] We show how the static dielectric function and other static characteristics of dense warm charged Fermi liquids can be obtained exclusively from the system static structure factor. The non-perturbative self-consistent method of moments is employed to extend onto quantum fluids, a similar reduction stemming from the fluctuation-dissipation theorem and other exact relations for classical one-component plasmas. The results are compared to and complement the numerical data obtained recently by the path-integral Monte Carlo method. Alternative theoretical approaches are discussed and employed as well.I.M.T. is grateful to M. Bonitz and T. Dornheim for several valuable discussions. The authors appreciate that M. Bonitz and T. Dornheim provided accurate path integral Monte Carlo simulation results. I.M.T. also acknowledges fruitful discussions with Yu. V. Arkhipov and L. Conde and the financial support provided by the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan (Project No. AP09260349).Ara-Bernad, J.; Coloma, L.; Tkachenko Gorski, IM. (2021). Static properties of a warm dense uniform electron gas. Physics of Plasmas. 28(11):1-17. https://doi.org/10.1063/5.0062259S117281
On the Correct Reading of Metaphysics V 7, 1017a 34–35. The Logic Behind Aristotle’s Example of the Diagonal
No full textThis paper aims to clarify the opposition between Alexander of Aphrodisias, followed by Hermann Bonitz on one side, and Thomas Aquinas, followed by Lambertus Marie de Rijk on the other, regarding the correct reading of an example proposed by Aristotle in Metaphysics V 7, 1017a 34–35, which involves the diagonal and its incommensurability with the side. The author aims to demonstrate that Aquinas’s interpretation (and De Rijk’s one) cannot be accepted and that we should follow Alexander of Aphrodisias and Bonitz
Quantum Fluctuations Approach to the Nonequilibrium -Approximation II: Density Correlations and Dynamic Structure Factor
No full textThe quantum dynamics of correlated fermionic or bosonic many-body systems
following external excitation can be successfully studied using nonequilibrium
Green functions (NEGF) or reduced density matrix methods. Approximations are
introduced via a proper choice of the many-particle selfenergy or decoupling of
the BBGKY-hierarchy, respectively. These approximations are based on Feynman's
diagram approaches or on cluster expansions into single-particle and
correlation operators. In a recent paper [E. Schroedter, J.-P. Joost, and M.
Bonitz, Cond. Matt. Phys. \textbf{25}, 23401 (2022)] we have presented a
different approach where, instead of equations of motion for the many-particle
NEGF (or density operators), equations for the correlation functions of
fluctuations are analyzed. In particular, we derived the stochastic GW and
polarization approximations that are closely related to the nonequilibrium GW
approximation. Here, we extend this approach to the computation of two-time
observables depending on the specific ordering of the underlying operators. In
particular, we apply this extension to the calculation of the density
correlation function and dynamic structure factor of correlated Hubbard
clusters in and out of equilbrium
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