scholarly journals Quantum Corrections to the Dynamics of the Gravitational System

2019 ◽  
Vol 64 (12) ◽  
pp. 1143
Author(s):  
V. V. Kuzmichev ◽  
V. E. Kuzmichev
Keyword(s):  
State Vector ◽  
Degrees Of Freedom ◽  
Wave Equations ◽  
The State ◽  
Constrained Systems ◽  
Short Introduction ◽  
Gravitational Systems ◽  
New Type ◽  
The Universe ◽  
Insight Into

A short introduction into the theory of quantum gravitational systems with a finite number of degrees of freedom is given. The theory is based on the method of quantization of constrained systems. The state vector of the system satisfies a set of wave equations which describes the time evolution of the system in the space of quantum fields. The state vector in such an approach can be normalized to unity. The theory permits a generalization to negative values of the scale factor and, being applied to cosmology, leads to the new understanding of the evolution of the universe. It gives an insight into the reasons why the regime of the expansion may change from acceleration to deceleration or vice versa, revealing a new type of quantum forces acting like dark matter and dark energy in the universe.

Quantenmechanik und Objektivierbarkeit/ Quantum Mechanics and Objective Reality

1970 ◽  
Vol 25 (12) ◽  
pp. 1954-1957 ◽  
Author(s):  
K. Baumann
Keyword(s):  
Quantum Mechanics ◽  
Density Matrix ◽  
State Vector ◽  
The State ◽  
Measuring Apparatus ◽  
Measuring Process ◽  
Objective Reality ◽  
Objective Description ◽  
The Universe

Abstract Quantum Mechanics and Objective Reality A Schrödinger function (or a density matrix) can he ascribed only to an object whose isolation time is larger than its time of revolution. This condition can never be satisfied for macroscopic bodies. Consequently, the "cut" between object and observer must not separate a macroscopic body (measuring apparatus) from the rest of the universe. Hence in an analysis of the measuring process, the state vector of the universe must be introduced. An interpretation of this state vector is given which provides an objective description of nature.

Tracking the Motion of Hidden Segments Using Kinematic Constraints and Kalman Filtering

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Kjartan Halvorsen ◽  
Christopher Johnston ◽  
Willem Back ◽  
Virgil Stokes ◽  
Håkan Lanshammar
Keyword(s):  
State Vector ◽  
Degrees Of Freedom ◽  
State Space Model ◽  
Nonlinear Function ◽  
The State ◽  
The Body ◽  
Joint Models ◽  
Kinematic Constraints ◽  
Generalized Coordinates ◽  
Marker Data

Motion capture for biomechanical applications involves in almost all cases sensors or markers that are applied to the skin of the body segments of interest. This paper deals with the problem of estimating the movement of connected skeletal segments from 3D position data of markers attached to the skin. The use of kinematic constraints has been shown previously to reduce the error in estimated segment movement that are due to skin and muscles moving with respect to the underlying segment. A kinematic constraint reduces the number of degrees of freedom between two articulating segments. Moreover, kinematic constraints can help reveal the movement of some segments when the 3D marker data otherwise are insufficient. Important cases include the human ankle complex and the phalangeal segments of the horse, where the movement of small segments is almost completely hidden from external observation by joint capsules and ligaments. This paper discusses the use of an extended Kalman filter for tracking a system of connected segments. The system is modeled using rigid segments connected by simplified joint models. The position and orientation of the mechanism are specified by a set of generalized coordinates corresponding to the mechanism’s degrees of motion. The generalized coordinates together with their first time derivatives can be used as the state vector of a state space model governing the kinematics of the mechanism. The data collected are marker trajectories from skin-mounted markers, and the state vector is related to the position of the markers through a nonlinear function. The Jacobian of this function is derived. The practical use of the method is demonstrated on a model of the distal part of the limb of the horse. Monte Carlo simulations of marker data for a two-segment system connected by a joint with three degrees of freedom indicate that the proposed method gives significant improvement over a method, which does not make use of the joint constraint, but the method requires that the model is a good approximation of the true mechanism. Applying the method to data on the movement of the four distal-most segments of the horse’s limb shows good between trial consistency and small differences between measured marker positions and marker positions predicted by the model.

Nonlinear Observers for Constrained Systems

2009 ◽  
Author(s):  
Giscard A. Kfoury ◽  
Nabil G. Chalhoub
Keyword(s):  
Degrees Of Freedom ◽  
Sliding Mode ◽  
The State ◽  
Constrained Systems ◽  
State Variables ◽  
Nonlinear Observers ◽  
Constraint Equations ◽  
Single Cylinder Engine ◽  
Robust Observers ◽  
Selection Of

Three procedures for designing robust observers to estimate the state variables of nonlinear constrained systems have been developed in this work. All observers are based on the sliding mode methodology and assume that the number of transducers matches that of the degrees of freedom of the system. The conceptual differences between the proposed observer designs are in the number and selection of the sliding surfaces along with the formulations pertaining to their nominal models. The observers have been applied to estimate the state variables of a crank-slider mechanism of a single cylinder engine. The simulation results demonstrate the capabilities of the observers in accurately estimating the state variables of the system, including the superfluous ones, in the presence of significant structured and unstructured uncertainties. In addition, the results show that the nominal constraint equations are satisfied by the estimated state variables.

scholarly journals The State and Modernity as Anthropological Topics: A Very Short Introduction

2008 ◽  
Vol 3 (3) ◽  
pp. 189-201
Author(s):  
Marina Simić
Keyword(s):  
Latin America ◽  
Political Theory ◽  
The State ◽  
Short Introduction ◽  
Insight Into

This paper aims to offer a brief introduction to anthropological studies of modernity and the state. I try to introduce some of the most important theoretical works in this field, built up in different ethnographic contexts ranging from Turkey to Latin America. I was trying to show some of the possibilities of the research of modernity and the state in anthropology emphasizing what anthropology can offer to wider debates on these topics. I argue that the ideas of modernity and the state are far more ambivalent then it sometimes may seem in European political theory and that anthropology can offer an insight into alternative forms of modernity and the state and into wider debates on these topics.

Operators and meaning of wave function

2016 ◽  
pp. 4039-4042
Author(s):  
Viliam Malcher
Keyword(s):  
Wave Function ◽  
Quantum Theory ◽  
State Vector ◽  
The State ◽  
Physical Significance ◽  
Central Problem ◽  
Quantum Mechanical ◽  
Mechanical Description ◽  
Quantum Mechanical Description ◽  
Interpretation Of Quantum Theory

The interpretation problems of quantum theory are considered. In the formalism of quantum theory the possible states of a system are described by a state vector. The state vector, which will be represented as |ψ> in Dirac notation, is the most general form of the quantum mechanical description. The central problem of the interpretation of quantum theory is to explain the physical significance of the |ψ>. In this paper we have shown that one of the best way to make of interpretation of wave function is to take the wave function as an operator.

The analysis is geometrically stable orbits of spacecraft remote sensing of the Еarth

2018 ◽  
Vol 15 (1) ◽  
pp. 12-22
Author(s):  
V. M. Artyushenko ◽  
D. Y. Vinogradov
Keyword(s):  
Remote Sensing ◽  
Gravitational Field ◽  
State Vector ◽  
Semimajor Axis ◽  
The State ◽  
Zonal Harmonics ◽  
The Earth ◽  
Conditions Of Stability

The article reviewed and analyzed the class of geometrically stable orbits (GUO). The conditions of stability in the model of the geopotential, taking into account the zonal harmonics. The sequence of calculation of the state vector of GUO in the osculating value of the argument of the latitude with the famous Ascoli-royski longitude of the ascending node, inclination and semimajor axis. The simulation is obtained the altitude profiles of SEE regarding the all-earth ellipsoid model of the gravitational field of the Earth given 7 and 32 zonal harmonics.

Galileo Unbound

2018 ◽  
Author(s):  
David D. Nolte
Keyword(s):  
Free Fall ◽  
The Sun ◽  
Quantum Field ◽  
Many Worlds ◽  
Quantum Particles ◽  
Light Rays ◽  
History Of ◽  
And Control ◽  
The Universe ◽  
Insight Into

Galileo Unbound: A Path Across Life, The Universe and Everything traces the journey that brought us from Galileo’s law of free fall to today’s geneticists measuring evolutionary drift, entangled quantum particles moving among many worlds, and our lives as trajectories traversing a health space with thousands of dimensions. Remarkably, common themes persist that predict the evolution of species as readily as the orbits of planets or the collapse of stars into black holes. This book tells the history of spaces of expanding dimension and increasing abstraction and how they continue today to give new insight into the physics of complex systems. Galileo published the first modern law of motion, the Law of Fall, that was ideal and simple, laying the foundation upon which Newton built the first theory of dynamics. Early in the twentieth century, geometry became the cause of motion rather than the result when Einstein envisioned the fabric of space-time warped by mass and energy, forcing light rays to bend past the Sun. Possibly more radical was Feynman’s dilemma of quantum particles taking all paths at once—setting the stage for the modern fields of quantum field theory and quantum computing. Yet as concepts of motion have evolved, one thing has remained constant, the need to track ever more complex changes and to capture their essence, to find patterns in the chaos as we try to predict and control our world.

Islamists between revolution and the state: an epilogue

2014 ◽  
Vol 7 (2) ◽  
pp. 283-298 ◽  
Author(s):  
Abdul Ghani Imad
Keyword(s):  
Political System ◽  
Arab World ◽  
The State ◽  
Social Needs ◽  
Political Actors ◽  
The Social ◽  
The Face ◽  
Heavy Burden ◽  
New Type ◽  
Political Realities

The problematic addressed in this article is the challenge initiated by the Arab revolutions to reform the Arab political system in such a way as to facilitate the incorporation of ‘democracy’ at the core of its structure. Given the profound repercussions, this issue has become the most serious matter facing the forces of change in the Arab world today; meanwhile, it forms the most prominent challenge and the most difficult test confronting Islamists. The Islamist phenomenon is not an alien implant that descended upon us from another planet beyond the social context or manifestations of history. Thus it cannot but be an expression of political, cultural, and social needs and crises. Over the years this phenomenon has presented, through its discourse, an ideological logic that falls within the context of ‘advocacy’; however, today Islamists find themselves in office, and in a new context that requires them to produce a new type of discourse that pertains to the context of a ‘state’. Political participation ‘tames’ ideology and pushes political actors to rationalize their discourse in the face of daily political realities and the necessity of achievement. The logic of advocacy differs from that of the state: in the case of advocacy, ideology represents an enriching asset, whereas in the case of the state, it constitutes a heavy burden. This is one reason why so much discourse exists within religious jurisprudence related to interest or necessity or balancing outcomes. This article forms an epilogue to the series of articles on religion and the state published in previous issues of this journal. It adopts the methodologies of ‘discourse analysis’ and ‘case studies’ in an attempt to examine the arguments presented by Islamists under pressure from the opposition. It analyses the experiences, and the constraints, that inhibit the production of a ‘model’, and monitors the development of the discourse, its structure, and transformations between advocacy, revolution and the state.

scholarly journals Hunting for Gravitational Quantum Spikes

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 49
Author(s):  
Andrzej Góźdź ◽  
Włodzimierz Piechocki ◽  
Grzegorz Plewa ◽  
Tomasz Trześniewski
Keyword(s):  
Initial Data ◽  
Fundamental Importance ◽  
Quantum Structures ◽  
Subtle Effect ◽  
Gravitational Systems ◽  
Numerical Tools ◽  
The Universe

We present the result of our examination of quantum structures called quantum spikes. The classical spikes that are known in gravitational systems, occur in the evolution of the inhomogeneous spacetimes. A different kind of spikes, which we name strange spikes, can be seen in the dynamics of the homogeneous sector of the Belinski–Khalatnikov–Lifshitz scenario. They can be made visible if the so-called inhomogeneous initial data are used. The question to be explored is whether the strange spikes may survive quantization. The answer is in the affirmative. However, this is rather a subtle effect that needs further examination using sophisticated analytical and numerical tools. The spikes seem to be of fundamental importance, both at classical and quantum levels, as they may serve as seeds of real structures in the universe.

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