Abstract We first present some basic properties of a quantum measure space. Compatibility of sets with respect to a quantum measure is studied and the center of a quantum measure space is characterized. We characterize quantum measures in terms of signed product measures. A generalization called a super-quantum measure space is introduced. Of a more speculative nature, we show that quantum measures may be useful for computing and predicting elementary particle masses.
Abstract We first present some basic properties of a quantum measure space. Compatibility of sets with respect to a quantum measure is studied and the center of a quantum measure space is characterized. We characterize quantum measures in terms of signed product measures. A generalization called a super-quantum measure space is introduced. Of a more speculative nature, we show that quantum measures may be useful for computing and predicting elementary particle masses.
Quantum measure spaces possess a certain “quantum weirdness” and lack some of the simplicity and intuitive nature of their classical counterparts. Much of this unusual behavior is due to a phenomenon called quantum interference, which is a recurrent theme in the present article. Because of this interference, quantum measures need not be additive but satisfy a more general condition called grade-2 additivity. Examples of quantum measure spaces such as “quantum coins” and particle-an tip article pairs are considered. Even more general spaces called super-quantum measure spaces are discussed. You don't need quantum mechanics or measure theory to understand this article.
Until recently, a quantum instrument was defined to be a completely positive operation-valued measure from the set of states on a Hilbert space to itself. In the last few years, this definition has been generalized to such measures between sets of states from different Hilbert spaces called the input and output Hilbert spaces. This article presents a theory of such instruments. Ways that instruments can be combined such as convex combinations, post-processing, sequential products, tensor products and conditioning are studied. We also consider marginal, reduced instruments and how these are used to define coexistence (compatibility) of instruments. Finally, we present a brief introduction to quantum measurement models where the generalization of instruments is essential. Many of the concepts of the theory are illustrated by examples. In particular, we discuss Holevo and Kraus instruments. Quanta 2023; 12: 27–40.
Abstract The so-called quantum measurement problems are solved from a new perspective. One of the main observations is that the basic entities of our world are particles, elementary or composite. It follows that each elementary process, hence each measurement process at its core, is a spacetime, pointlike, event. Another key idea is that, when a microsystem ψ gets into contact with the experimental device, factorization of ψ rapidly fails and entangled mixed states appear. The wave functions for the microsystem-apparatus coupled system for different measurement outcomes then lack overlapping spacetime support. It means that the aftermath of each measurement is a single term in the sum: a “wave-function collapse”. Our discussion leading to a diagonal density matrix, ρ = diag(|c 1|2,…,|cn |2,…) shows how the information encoded in the wave function <?CDATA $|\psi \rangle =\displaystyle {\sum }_{n}{c}_{n}|n\rangle $?> | ψ 〉 = ∑ n c n | n 〉 gets transcribed, via entanglement with the experimental device and environment, into the relative frequencies Pn = |cn |2 for various experimental outcomes F = fn . Our discussion represents the first, significant steps towards filling in the logical gaps in the conventional interpretation based on Born’s rule, replacing it with a clearer understanding of quantum mechanics. Accepting objective reality of quantum fluctuations, independent of any experiments, and independently of human presence, one renounces the idea that in a fundamental, complete theory of Nature the result of each single experiment must necessarily be predictable.
This paper proposes mass interaction principle (MIP) as: the particles will be subjected to the random frictionless quantum Brownian motion by the collision of space time particle (STP) prevalent in spacetime. The change in the amount of action of the particles during each collision is an integer multiple of the Planck constant h. The motion of particles under the action of STP is a quantum Markov process. Under this principle, we infer that the statistical inertial mass of a particle is a statistical property that characterizes the difficulty of particle diffusion in spacetime. Starting from this principle, this article has the following six aspects of work: First, we derive the mass-diffusion coefficient uncertainty and the quantized commutation, and derive the most basic coordinate-momentum uncertainty and time-energy uncertainty of quantum mechanics, and then clearly reveal the particle-wave duality, which are properties exhibited by particles collided by STP. Second, we created the three decompositions of particles velocity. The comprehensive property of three velocities deduced the equation of motion of the particle as Schrodinger equation, and made a novel interpretation of Heisenberg’s uncertainty principle and Feynman’s path integral expression. And reexamine the quantum measurement problem, so that the EPR paradox can be explained in a self-consistent manner. Third, we reinterpret the physical origin of quantum spins. Each spacetime random impact not only gives the particle of matter the action of a Planck constant , but also produces the quantum fluctuation properties of the material particles. Futhermore, the quantum spin properties of the material particles are also produced, which reveals the statistical quality of 1/2 spin particles and the coexistence relationship of their spins. The particle spin properties ultimately reflect the spacetime properties of STP and particles, which leads to an important result that any spin 1/2 elementary particles will be massive. Fourth, we derive the physical origin of the special relativity, and prove that the hypothesis of constant speed of light is actually the intrinsic property of spacetime. This naturally leads to the three basic inferences of the special theory of relativity, namely, “mass enhancement”, “time dilation” and “length contraction” effects. Fifth, we can perfectly explain the nature of photons based on the topological and dynamic properties of STP, thus naturally obtain the complete electromagnetic theory and all important properties of charge. Sixth, we naturally derive the gravitation from the interaction of the fundamental particles of microscopic matter, namely the massive fermion and STP. Furthermore, we can judge from the overall perspective of modern physics that the inertia mass of fermions must be equal to the gravitational mass. We have obtained the equivalent principle combined with Newton’s universal gravitation, from which we can derive all the important contents of general relativity. Both inertial mass and gravitational mass are no longer the basic physical quantities. The two are indeed equivalent, which come from the statistical mass of STP collisions. This paper shows that STP can interact with matter particles in space time. The particles of matter are affected by the impact of STP and change their motional state. The mass of a particle is a statistical property exhibited by STP collision. Under the MIP framework of interaction between STP and matter particles, the relativistic quantum electromagnetic and spin properties of particles are all self-consistent. The relativistic behavior and quantum behavior of matter particles with statistical mass are all derived from the collision of STP on matter particles. We have systematically solved all the basic problems of modern physics with MIP, which is the common origin of special theory of relativity, general theory of relativity, electromagnetic theory and quantum mechanics.
In this paper, we study implications of the geometrical nature of space- time for some of the basic tenets of quantum mechanics. That is, we study two different implications of the principle of general covariance; first we quantize a reparametrization invariant theory, the free particle in Minkowski spacetime and point out in detail where this theory fails (no- tably these comments appear to be missing in the literature). Second we study the covariance of quantum field theory and show how it connects to causality, the outcome of this study is that QFT is what we shall call ultra weakly covariant with respect to the background spacetime. Third, we treat the question of whether evolution in quantum theory (apart from the measurement act) needs to be unitary, it is easily shown that a per- fectly satisfying probabilistic interpretation exists which does not require unitary evolution. Fourth, we speculate on some modifications quantum theory should undergo in order for it to be generally covariant. The results in this paper hint at a profound change of the theory in which causality as a fundamental principle is abandonned.