scholarly journals Symmetry Constrained Decoherence of Conditional Expectation Values

Universe ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 46 ◽  
Author(s):  
M. Mohammady ◽  
Alessandro Romito
Keyword(s):  
Conditional Expectation ◽  
Sufficient Conditions ◽  
Specific Model ◽  
Quantum Mechanical ◽  
Conserved Quantities ◽  
System State ◽  
Quantum Thermodynamics ◽  
Expectation Values ◽  
Thermal Measurements

Conditional expectation values of quantum mechanical observables reflect unique non-classical correlations, and are generally sensitive to decoherence. We consider the circumstances under which such sensitivity to decoherence is removed, namely, when the measurement process is subjected to conservation laws. Specifically, we address systems with additive conserved quantities and identify sufficient conditions for the system state such that its coherence plays no role in the conditional expectation values of observables that commute with the conserved quantity. We discuss our findings for a specific model where the system-detector coupling is given by the Jaynes-Cummings interaction, which is relevant to experiments tracking trajectories of qubits in cavities. Our results clarify, among others, the role of coherence in thermal measurements in current architectures for quantum thermodynamics experiments.

scholarly journals Quantum postulate vs. quantum nonlocality: on the role of the Planck constant in Bell’s argument

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Andrei Khrennikov
Keyword(s):  
Quantum Nonlocality ◽  
Quantum Mechanical ◽  
Quantum Foundations ◽  
Planck Constant ◽  
Variable Model ◽  
Basic Principles ◽  
Fundamental Feature ◽  
Hidden Variable ◽  
Bell Model

AbstractWe present a quantum mechanical (QM) analysis of Bell’s approach to quantum foundations based on his hidden-variable model. We claim and try to justify that the Bell model contradicts to the Heinsenberg’s uncertainty and Bohr’s complementarity principles. The aim of this note is to point to the physical seed of the aforementioned principles. This is the Bohr’s quantum postulate: the existence of indivisible quantum of action given by the Planck constant h. By contradicting these basic principles of QM, Bell’s model implies rejection of this postulate as well. Thus, this hidden-variable model contradicts not only the QM-formalism, but also the fundamental feature of the quantum world discovered by Planck.

The statist neo-institutionalism of Acemoglu and Robinson

2021 ◽  
Author(s):  
Deirdre Nansen McCloskey
Keyword(s):  
Sufficient Conditions ◽  
Modern World ◽  
Social Causation ◽  
Good Guide

In a long review of Acemoglu and Robinson’s 2019 The Narrow Corridor McCloskey praises their scholarship but criticizes their relentless statism—their enthusiasts for a bigger and bigger Stato, so long as it is somehow “caged.” Their case is mechanical, materialist, and structuralist, none of which is a good guide to history or politics. Their theory of social causation mixes up necessary with sufficient conditions, though they are not unusual among political scientists an economists in doing so. They downplay the role of ideas, which after all made the modern world through liberalism. They recognize how dangerous the modern “capable” state can be, what they call The Leviathan, after Hobbes. But their construal of “liBerty” is the provision of goodies to children by a beneficent Leviathan. It is not the adultism that in fact made the modern world of massive enrichment and true liberty. Their vision is deeply illiberal, and mistaken as science.

scholarly journals Детерминизм локального атомного упорядочения в монослоях золота в формировании их электронной структуры

2022 ◽  
Vol 64 (3) ◽  
pp. 303
Author(s):  
В.Л. Карбовский ◽  
А.А. Романский ◽  
Л.И. Карбовская ◽  
В.В. Стонис
Keyword(s):  
Coordination Sphere ◽  
Electronic States ◽  
Mutual Arrangement ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
The Third ◽  
Long Range Interactions ◽  
Valence Bands ◽  
D Orbitals

The total and partial densities of electronic states of gold monolayer structures of different symmetry are calculated by the quantum mechanical calculations methods in the DFT approximation. It is shown that the first coordination sphere is determinant in the formation of the fine structure and the extent of the valence bands of the monolayer gold structures under study. The peaks splitting of the TDOS curve, which leads to its finer structure, is influenced not only by the lengths of interatomic bonds but also by the mutual arrangement of atoms. The influence of long-range interactions on the electronic structure of gold monolayers has been established. For example, for the (110) plane, a change in the atomic ordering in the third coordination sphere as a result of the introduction of a vacancy leads to noticeable changes in the TDOS curve, which indicates either a significant role of the atoms of the third coordination sphere or a significant redistribution of the interaction of d-orbitals of different symmetries of close neighbours. A correlation between the packing density, as well as the number of neighbours in the first coordination sphere, and the width of the energy band of gold monolayers has been established.

scholarly journals Experimental and numerical investigations on heat transfer in fused filament fabrication 3D-printed specimens

2021 ◽  
Author(s):  
Nathalie Ramos ◽  
Christoph Mittermeier ◽  
Josef Kiendl
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer Coefficient ◽  
Numerical Data ◽  
Fused Filament Fabrication ◽  
Thermal Boundary Conditions ◽  
Thermal Measurements ◽  
Stress Prediction ◽  
3D Printed ◽  
Air Void

AbstractA good understanding of the heat transfer in fused filament fabrication is crucial for an accurate stress prediction and subsequently for repetitive, high-quality printing. This work focuses on two challenges that have been presented when it comes to the accuracy and efficiency in simulating the heat transfer in the fused filament fabrication process. With the prospect of choosing correct thermal boundary conditions expressing the natural convection between printed material and its environment, values for the convective heat transfer coefficient and ambient temperature were calibrated through numerical data fitting of experimental thermal measurements. Furthermore, modeling simplifications were proposed for an efficient numerical discretization of infill structures. Samples were printed with varying infill characteristics, such as varying air void size, infill densities and infill patterns. Thermal measurements were performed to investigate the role of these parameters on the heat transfer and based on these observations, possible modeling simplifications were studied in the numerical simulations.

scholarly journals Application of the quantum mechanical hypervirial theorems to even-power series potentials

2020 ◽  
Vol 5 ◽  
pp. 104
Author(s):  
T. E. Liolios ◽  
M. E. Grypeos
Keyword(s):  
Power Series ◽  
Excited States ◽  
Energy Operator ◽  
Quantum Mechanical ◽  
Expectation Values ◽  
Gaussian Potential ◽  
Energy Eigenvalues ◽  
The Mean ◽  
Potential Parameters ◽  
Feynman Theorem

The class of the even-power series potentials:V(r)=-D+ Σ_k^{\infty} V_kλ^kr^{2k+2}, Vo=ω^2>0, is studied with the aim of obtaining approximate analytic ex­pressions for the energy eigenvalues, the expectation values for the potential and the kinetic energy operator, and the mean square radii of the orbits of a particle in its ground and excited states. We use the Hypervirial Theorems (HVT) in conjunction with the Hellmann-Feynman Theorem (HFT) which provide a very powerful scheme especially for the treatment of that type of potentials, as previous studies have shown. The formalism is reviewed and the expressions of the above mentioned quantities are subsequently given in a convenient way in terms of the potential parameters and the mass of the particle, and are then applied to the case of the Gaussian potential and to the potential V(r)=-D/cosh^2(r/R). These expressions are given in the form of series expansions, the first terms of which yield in quite a number of cases values of very satisfactory accuracy.

The role of the basis set and the level of quantum mechanical theory in the prediction of the structure and reactivity of cisplatin

2012 ◽  
Vol 33 (29) ◽  
pp. 2292-2302 ◽  
Author(s):  
Diego Paschoal ◽  
Bruna L. Marcial ◽  
Juliana Fedoce Lopes ◽  
Wagner B. De Almeida ◽  
Hélio F. Dos Santos
Keyword(s):  
Basis Set ◽  
Quantum Mechanical ◽  
Mechanical Theory ◽  
Quantum Mechanical Theory

The role of aziridinyl cyclophosphazenes and related compounds as anticancer agents. A tentative quantum mechanical approach

1982 ◽  
Vol 88 (3-4) ◽  
pp. 317-324 ◽  
Author(s):  
Guy Guerch ◽  
Jean-Paul Faucher ◽  
Marcel Graffeuil ◽  
Gaston Levy ◽  
Jean-Francois Labarre
Keyword(s):  
Anticancer Agents ◽  
Quantum Mechanical ◽  
Mechanical Approach ◽  
Quantum Mechanical Approach ◽  
Related Compounds
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