Conceptual Issues in Canonical Quantum Gravity and Cosmology
... on a three-dimensional manifold Σ. In retrospect, this is not surprising. A classical spacetime as a succession of three-dimensional hypersurfaces is fully analogous to a particle trajectory in mechanics (a succession of positions). In the same way that the particle trajectory vanishes in quantum me ...
... on a three-dimensional manifold Σ. In retrospect, this is not surprising. A classical spacetime as a succession of three-dimensional hypersurfaces is fully analogous to a particle trajectory in mechanics (a succession of positions). In the same way that the particle trajectory vanishes in quantum me ...
- Philsci
... truth.1 Scientific theories may or may not be true, what is important is that they are empirically adequate in the sense that they are true with respect to observation. Instrumentalists go even further in their denial of truth as an indispensable epistemic value. For them it is enough if theories ar ...
... truth.1 Scientific theories may or may not be true, what is important is that they are empirically adequate in the sense that they are true with respect to observation. Instrumentalists go even further in their denial of truth as an indispensable epistemic value. For them it is enough if theories ar ...
1 Quantization of the Electromagnetic Field
... potential. If we realise that the derivative is nothing but the limit of the difference of the vector potential between neighboring points and at the same time, we can argue that the magnetic field is the limit of a linear combination of vector potentials at different points. Since the vector poten ...
... potential. If we realise that the derivative is nothing but the limit of the difference of the vector potential between neighboring points and at the same time, we can argue that the magnetic field is the limit of a linear combination of vector potentials at different points. Since the vector poten ...
Naturalness, Hierarchy and Physics Beyond the Standard Model
... • Till ‘03 or so hierarchy and naturalness were the main problems to address: why is the weak scale so small compared to the Planck scale and why is the Higgs boson’s mass stable under radiative corrections? • Indeed if quantum field theories are only an “effective tool” (Wilsonian approach) one has ...
... • Till ‘03 or so hierarchy and naturalness were the main problems to address: why is the weak scale so small compared to the Planck scale and why is the Higgs boson’s mass stable under radiative corrections? • Indeed if quantum field theories are only an “effective tool” (Wilsonian approach) one has ...
Quantum Transport Theory in Heterostructure Devices
... A general feature of electron devices is that they are of use only when connected to a circuit, and to be so connected any device must possess at least two terminals, contacts, or leads. As a consequence, every device is a open system with respect to electron flow [5]. This is the overriding fact tha ...
... A general feature of electron devices is that they are of use only when connected to a circuit, and to be so connected any device must possess at least two terminals, contacts, or leads. As a consequence, every device is a open system with respect to electron flow [5]. This is the overriding fact tha ...
Research Status, Winter 2009 - Cove
... f (0) 80 mod15 1 f (1) 81 mod15 8 f (2) 82 mod15 4 f (3) 83 mod15 2 f (4) 84 mod15 1 f (5) 85 mod15 8 f (6) 86 mod15 4 f (7) 87 mod15 2 f (8) 88 mod15 1 f (9) 89 mod15 8 f (10) 810 mod15 4 f (11) 811 mod15 2 f (12) 812 mod15 1 f (13) 813 mod 15 ...
... f (0) 80 mod15 1 f (1) 81 mod15 8 f (2) 82 mod15 4 f (3) 83 mod15 2 f (4) 84 mod15 1 f (5) 85 mod15 8 f (6) 86 mod15 4 f (7) 87 mod15 2 f (8) 88 mod15 1 f (9) 89 mod15 8 f (10) 810 mod15 4 f (11) 811 mod15 2 f (12) 812 mod15 1 f (13) 813 mod 15 ...
Renormalization
In quantum field theory, the statistical mechanics of fields, and the theory of self-similar geometric structures, renormalization is any of a collection of techniques used to treat infinities arising in calculated quantities.Renormalization specifies relationships between parameters in the theory when the parameters describing large distance scales differ from the parameters describing small distances. Physically, the pileup of contributions from an infinity of scales involved in a problem may then result in infinities. When describing space and time as a continuum, certain statistical and quantum mechanical constructions are ill defined. To define them, this continuum limit, the removal of the ""construction scaffolding"" of lattices at various scales, has to be taken carefully, as detailed below.Renormalization was first developed in quantum electrodynamics (QED) to make sense of infinite integrals in perturbation theory. Initially viewed as a suspect provisional procedure even by some of its originators, renormalization eventually was embraced as an important and self-consistent actual mechanism of scale physics in several fields of physics and mathematics. Today, the point of view has shifted: on the basis of the breakthrough renormalization group insights of Kenneth Wilson, the focus is on variation of physical quantities across contiguous scales, while distant scales are related to each other through ""effective"" descriptions. All scales are linked in a broadly systematic way, and the actual physics pertinent to each is extracted with the suitable specific computational techniques appropriate for each.