Quantum mechanics is a scientific theory that seeks to describe atomic and subatomic particles (or quantum particles) as well as the interaction among them. Such particles include electrons, protons, neutrons, and photons. In classical mechanics, a particle’s future state is described with certainty once its present state is known. At any given moment, its momentum and position are determined w...

I maintain that quantum mechanics is fundamentally about a system of N particles evolving in three-dimensional space, not the wave function evolving in 3N-dimensional space. 1. Introduction. What is quantum mechanics fundamentally about? I believe that quantum mechanics is fundamentally about particles: quantum mechanics describes the behavior of systems of particles evolving in three-dimension...

Familiar textbook quantum mechanics assumes a fixed background spacetime to define states on spacelike surfaces and their unitary evolution between them. Quantum theory has changed as our conceptions of space and time have evolved. But quantum mechanics needs to be generalized further for quantum gravity where spacetime geometry is fluctuating and without definite value. This paper reviews a fu...

Quantum mechanics (QM) is the modern physical theory of very small (microscopic) systems, typically atomic-sized or smaller. Along with Einstein's theory of relativity, QM represented a major revolution in our understanding of physics, which was previously described by Newtonian (classical) mechanics. Problems with Classical Physics The enormous success of Newtonian mechanics led Lord Kelvin to...

Ever since the advent of quantum mechanics, it has been clear that the atoms composing matter do not obey Newton’s laws. Instead, their behavior is described by the Schrödinger equation. Surprisingly though, until recently, no clear explanation was given for why everyday objects, which are merely collections of atoms, are observed to obey Newton’s laws. It would seem that, if quantum mechanics ...

We treat space and time as bona fide quantum degrees of freedom on an equal footing in Hilbert space. Motivated by considerations gravity, we focus a paradigm dealing with linear, first-order Hamiltonian momentum constraints that lead to emergent features temporal spatial translations. Unlike the conventional treatment, show Klein-Gordon Dirac equations relativistic mechanics can be unified our...

From Classical to Quantum Mechanics: " How to translate physical ideas into mathematical language " Abstract In this paper, we investigate the connection between Classical and Quantum Mechanics by dividing Quantum Theory in two parts:-General Quantum Axiomatics (a system is described by a state in a Hilbert space, observables are self-adjoints operators and so on...)-Quantum Mechanics properly ...

We show that, in spite of a rather common opinion, quantum mechanics can be represented as an approximation of classical statistical mechanics. The approximation under consideration is based on the ordinary Taylor expansion of physical variables. The quantum contribution is given by the term of the second order. To escape technical difficulties related to the infinite dimension of phase space f...

We show that, assuming that quantum mechanics holds locally, the finite speed of information is the principle that limits all possible correlations between distant parties to be quantum mechanical as well. Local quantum mechanics means that a Hilbert space is assigned to each party, and then all local positive-operator-valued measurements are (in principle) available; however, the joint system ...