Questions tagged [quantum-mechanics]
Quantum mechanics describes the microscopic properties of nature in a regime where classical mechanics no longer applies. It explains phenomena such as the wave-particle duality, quantization of energy, and the uncertainty principle and is generally used in single-body systems. Use the quantum-field-theory tag for the theory of many-body quantum-mechanical systems.
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Gaussian integration with operator-valued sources and time ordering
I have a coherent-state path integral of complex scalar fields $\psi^+,\psi^-$ which I want to integrate out, but the linear terms are operators.
$$ \mathbb{P}(t) = \int D[\psi^+]D[\psi^-] \exp(S_0)T\...
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How do we define time-ordering operations in QFT?
Given two bosonic operators $A$, $B$ (in the Heisenberg picture) in a QFT, the time-ordered product of $A$ and $B$ is defined as
$$
T\{A(t_1)B(t_2)\}=\theta(t_1-t_2)A(t_1)B(t_2)+\theta(t_2-t_1)B(t_2)A(...
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Can deterministic particle trajectories with an internal oscillatory phase produce interference without a wave equation? [closed]
I’ve been developing a toy model where each particle evolves in two time parameters:
A classical propagation time t and an internal oscillatory time τ(t).
Youtube here
The transverse coordinate is ...
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Can entropy growth and quantization emerge from partial tracing a pure state?
I would like to ask whether the following conceptual framework is mathematically consistent within standard quantum theory and statistical mechanics.
Assume the total universe is described by a pure ...
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Is zero-point energy a mathematical artifact?
From Wikipedia, Pauli has said in his Nobel lecture that "It is clear that this zero-point energy has no physical reality". This feels natural - I've always been slightly puzzled by the ...
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Nested double-slit experiment, interference or not? [closed]
Suppose we perform the usual double-slit experiment, but we place a perfectly isolated box with a one-slit input and output before the initial double slits.
Inside the box, a double-slit experiment ...
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Double slit experiment difference (classical vs quantum) if any
I am learning quantum mechanics and am confused about the double slit experiment involving shooting of a single photon at a time through the slits. It is said in the books that if we try to measure ...
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Commuting operators and simultaneous eigenstates [duplicate]
If two operators commute, they share simultaneous eigenvectors. I understand the proof of this statement, however, I'm trying to gain physical insight as to what this means practically. When two ...
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Toward a Universal Hamiltonian: A Unified View of Energy and Physical Law [closed]
Abstract
Modern physics is fragmented across multiple frameworks - string theory, quantum field theory, loop quantum
gravity, causal set theory, and emergent spacetime models - each accurately ...
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Can fundamental physical constants be explained via dimensions linked to π, e, and φ? [closed]
I'm developing a theoretical framework where fundamental mathematical constants π (3.14159...), e (2.71828...), and φ (1.61803...) are treated as compactified dimensions in an extended spacetime.
Core ...
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Can any Foulis&Randall Test Space be equivalently formulated in terms of Yes/No Tests?
By test space I specifically mean this (RG) (see Section 5.1 for formal definition). A somewhat more thorough (and more specific) treatment is the article "Test Spaces" by Alexander Wilce, ...
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Stability and extensivity of matter in quantum mechanics
Consider a (non-relativistic, zero-temperature) system of $N$ negatively charged fermions and $M$ (static) positively charged nuclei which obeys the stability of the second kind: Roughly speaking, the ...
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Are quantum wavefunctions required to be analytic?
In quantum mechanics, a 1D wavefunction $\psi(x)$ is generally a complex-valued function of the spatial coordinate $x$. It is usually required to be square-integrable and sufficiently smooth so that ...
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Do all operators which fulfil mathematical conditions in Quantum Mechanics correspond to an observable? [duplicate]
In my understanding of Quantum mechanics, which is demonstrably limited, Operators have corresponding observables. I imagine it like operators helping draw a graph, with probability on the y-axis and ...
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Alternatives to the collapse of the wave function [closed]
The equations of classical physics are time reversible -- unchanged when $t$ is replaced by $-t$. The Schrodinger equation in quantum mechanics is time reversible -- unchanged when $t$ is replaced by ...
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