Tag: QFT
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Vacuum Fluctuations
Introduction Quantum mechanics introduces an intriguing concept: vacuum fluctuations. This principle suggests that even in a perfect vacuum, there are tiny, momentary changes in energy. Unlike classical physics, which describes a vacuum as an absolute emptiness, quantum physics sees it as a sea of transient particles and antiparticles that continuously form and annihilate. Vacuum State…
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Hawking Radiation
Introduction Hawking Radiation is a theoretical prediction made by physicist Stephen Hawking in 1974. It is a quantum mechanical phenomenon in which black holes emit thermal radiation due to quantum effects near the event horizon. This stands in stark contrast to the classical prediction of general relativity, which asserts that black holes should not emit…
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Ward–Takahashi Identity
Introduction The Ward–Takahashi Identity, named after physicists J.C. Ward and Y. Takahashi, is a key result in quantum electrodynamics (QED) and quantum field theory (QFT). It ensures the conservation of electric charge in QED, and more generally, the conservation of current in QFT. Statement of the Ward–Takahashi Identity Identity The Ward-Takahashi identity can be written…
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Quantum Tunneling
Introduction Quantum tunneling is a quantum mechanical phenomenon where particles can penetrate through a potential energy barrier that they could not surmount according to classical physics. It arises from the wave-like nature of particles described by the principles of quantum mechanics. Basic Explanation of Quantum Tunneling In classical physics, a particle would need to have…
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Quantum Field Theory (QFT)
Introduction Quantum Field Theory (QFT) is a theoretical framework that combines the principles of quantum mechanics and special relativity to describe the behavior of quantum particles and fields. It is the basis for our understanding of elementary particle physics, and it underpins the standard model of particle physics. Basics of Quantum Fields In QFT, particles…
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Magnetic Monopoles
Introduction Magnetic monopoles are hypothetical particles that carry a single, isolated magnetic pole – either a north pole or a south pole. In contrast, every known particle that carries a magnetic field has both a north and a south pole. The concept of magnetic monopoles arises from the symmetry in Maxwell’s equations and the concept…