The physical meaning of the magnetic scalar potential and its use in the design of hermetic electromagnetic coils

In a previous paper the absorption of γ-rays in the K-X-ray levels of the atom in which they are emitted was calculated according to the Quantum Mechanics, supposing the γ-rays to be emitted from a doublet of moment f ( t ) at the centre of the atom. The non-relativity wave equation derived from the relativity wave equation for an electron of charge — ε moving in an electro-magnetic field of vector potential K and scalar potential V is h 2 ∇ 2 ϕ + 2μ ( ih ∂/∂ t + εV + ih ε/μ c (K. grad)) ϕ = 0. (1) Suppose, however, that K involves the space co-ordinates. Then, (K. grad) ϕ ≠ (grad . K) ϕ , and the expression (K . grad) ϕ is not Hermitic. Equation (1) cannot therefore be the correct non-relativity wave equation for a single electron in an electron agnetic field, and we must substitute h 2 ∇ 2 ϕ + 2μ ( ih ∂/∂ t + εV) ϕ + ih ε/ c ((K. grad) ϕ + (grad. K) ϕ ) = 0. (2)

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Seeking the Good Fitting Procedure of PALS Polymer Spectra

Materials Science Forum ◽

10.4028/www.scientific.net/msf.607.64 ◽

2008 ◽

Vol 607 ◽

pp. 64-66

Author(s):

Nicolas Laforest ◽

Jérémie De Baerdemaeker ◽

Corine Bas ◽

Charles Dauwe

Keyword(s):

Experimental Data ◽

Low Temperature ◽

Positron Annihilation ◽

Physical Meaning ◽

Lifetime Measurements ◽

Positron Annihilation Lifetime ◽

Fitting Procedure ◽

Fitting Procedures ◽

Blob Model

Positron annihilation lifetime measurements on polymethylmethacrylate (PMMA) at low temperature were performed. Different discrete fitting procedures have been used to analyze the experimental data. It shows that the extracted parameters depend strongly on the fitting procedure. The physical meaning of the results is discussed. The blob model seems to give the best annihilation parameters.

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Systematics of type IIA moduli stabilisation

Journal of High Energy Physics ◽

10.1007/jhep11(2020)113 ◽

2020 ◽

Vol 2020 (11) ◽

Author(s):

Fernando Marchesano ◽

David Prieto ◽

Joan Quirant ◽

Pramod Shukla

Keyword(s):

Scalar Potential ◽

Systematic Search ◽

Stability Criteria ◽

De Sitter ◽

Large Subset

Abstract We analyse the flux-induced scalar potential for type IIA orientifolds in the presence of p-form, geometric and non-geometric fluxes. Just like in the Calabi-Yau case, the potential presents a bilinear structure, with a factorised dependence on axions and saxions. This feature allows one to perform a systematic search for vacua, which we implement for the case of geometric backgrounds. Guided by stability criteria, we consider configurations with a particular on-shell F-term pattern, and show that no de Sitter extrema are allowed for them. We classify branches of supersymmetric and non-supersymmetric vacua, and argue that the latter are perturbatively stable for a large subset of them. Our solutions reproduce and generalise previous results in the literature, obtained either from the 4d or 10d viewpoint.

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Particle Filtering Based Remaining Useful Life Prediction for Electromagnetic Coil Insulation

Sensors ◽

10.3390/s21020473 ◽

2021 ◽

Vol 21 (2) ◽

pp. 473

Author(s):

Haifeng Guo ◽

Aidong Xu ◽

Kai Wang ◽

Yue Sun ◽

Xiaojia Han ◽

...

Keyword(s):

Particle Filtering ◽

Remaining Useful Life ◽

Electrical Parameters ◽

Degradation Model ◽

Accelerated Degradation ◽

Insulation Failure ◽

Electromagnetic Coils ◽

Degradation Monitoring ◽

Insulation Degradation ◽

Useful Life

Electromagnetic coils are one of the key components of many systems. Their insulation failure can have severe effects on the systems in which coils are used. This paper focuses on insulation degradation monitoring and remaining useful life (RUL) prediction of electromagnetic coils. First, insulation degradation characteristics are extracted from coil high-frequency electrical parameters. Second, health indicator is defined based on insulation degradation characteristics to indicate the health degree of coil insulation. Finally, an insulation degradation model is constructed, and coil insulation RUL prediction is performed by particle filtering. Thermal accelerated degradation experiments are performed to validate the RUL prediction performance. The proposed method presents opportunities for predictive maintenance of systems that incorporate coils.

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Harmonic hybrid inflation

Journal of High Energy Physics ◽

10.1007/jhep12(2020)161 ◽

2020 ◽

Vol 2020 (12) ◽

Author(s):

Federico Carta ◽

Nicole Righi ◽

Yvette Welling ◽

Alexander Westphal

Keyword(s):

Domain Wall ◽

Symmetry Breaking ◽

Initial Conditions ◽

Scalar Potential ◽

Field Range ◽

Slow Roll ◽

Minimal Form ◽

Wide Range ◽

Hybrid Inflation ◽

Type Iib String Theory

Abstract We present a mechanism for realizing hybrid inflation using two axion fields with a purely non-perturbatively generated scalar potential. The structure of the scalar potential is highly constrained by the discrete shift symmetries of the axions. We show that harmonic hybrid inflation generates observationally viable slow-roll inflation for a wide range of initial conditions. This is possible while accommodating certain UV arguments favoring constraints f ≲ MP and ∆ϕ60 ≲ MP on the axion periodicity and slow-roll field range, respectively. We discuss controlled ℤ2-symmetry breaking of the adjacent axion vacua as a means of avoiding cosmological domain wall problems. Including a minimal form of ℤ2-symmetry breaking into the minimally tuned setup leads to a prediction of primordial tensor modes with the tensor-to-scalar ratio in the range 10−4 ≲ r ≲ 0.01, directly accessible to upcoming CMB observations. Finally, we outline several avenues towards realizing harmonic hybrid inflation in type IIB string theory.

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Neutrino masses, vacuum stability and quantum gravity prediction for the mass of the top quark

Journal of High Energy Physics ◽

10.1007/jhep01(2021)180 ◽

2021 ◽

Vol 2021 (1) ◽

Author(s):

Guillem Domènech ◽

Mark Goodsell ◽

Christof Wetterich

Keyword(s):

Quantum Gravity ◽

Top Quark ◽

Quark Mass ◽

Scalar Potential ◽

Planck Scale ◽

Neutrino Masses ◽

Top Quark Mass ◽

Vacuum Stability ◽

Intermediate Scale ◽

Yukawa Couplings

Abstract A general prediction from asymptotically safe quantum gravity is the approximate vanishing of all quartic scalar couplings at the UV fixed point beyond the Planck scale. A vanishing Higgs doublet quartic coupling near the Planck scale translates into a prediction for the ratio between the mass of the Higgs boson MH and the top quark Mt. If only the standard model particles contribute to the running of couplings below the Planck mass, the observed MH∼ 125 GeV results in the prediction for the top quark mass Mt∼ 171 GeV, in agreement with recent measurements. In this work, we study how the asymptotic safety prediction for the top quark mass is affected by possible physics at an intermediate scale. We investigate the effect of an SU(2) triplet scalar and right-handed neutrinos, needed to explain the tiny mass of left-handed neutrinos. For pure seesaw II, with no or very heavy right handed neutrinos, the top mass can increase to Mt ∼ 172.5 GeV for a triplet mass of M∆ ∼ 108GeV. Right handed neutrino masses at an intermediate scale increase the uncertainty of the predictions of Mt due to unknown Yukawa couplings of the right-handed neutrinos and a cubic interaction in the scalar potential. For an appropriate range of Yukawa couplings there is no longer an issue of vacuum stability.

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Effective Scalar Potential in Asymptotically Safe Quantum Gravity

Universe ◽

10.3390/universe7020045 ◽

2021 ◽

Vol 7 (2) ◽

pp. 45

Author(s):

Christof Wetterich

Keyword(s):

Quantum Gravity ◽

Top Quark ◽

Particle Physics ◽

Scalar Potential ◽

Scalar Fields ◽

The Standard Model ◽

Scaling Potential ◽

Realistic Description ◽

The Masses ◽

Dynamical Dark Energy

We compute the effective potential for scalar fields in asymptotically safe quantum gravity. A scaling potential and other scaling functions generalize the fixed point values of renormalizable couplings. The scaling potential takes a non-polynomial form, approaching typically a constant for large values of scalar fields. Spontaneous symmetry breaking may be induced by non-vanishing gauge couplings. We strengthen the arguments for a prediction of the ratio between the masses of the top quark and the Higgs boson. Higgs inflation in the standard model is unlikely to be compatible with asymptotic safety. Scaling solutions with vanishing relevant parameters can be sufficient for a realistic description of particle physics and cosmology, leading to an asymptotically vanishing “cosmological constant” or dynamical dark energy.

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Solving puzzles in deformed JT gravity: phase transitions and non-perturbative effects

Journal of High Energy Physics ◽

10.1007/jhep04(2021)030 ◽

2021 ◽

Vol 2021 (4) ◽

Author(s):

Clifford V. Johnson ◽

Felipe Rosso

Keyword(s):

Phase Structure ◽

Scalar Potential ◽

String Equation ◽

Two Dimensional ◽

Leading Order ◽

Classical Analysis ◽

First Order ◽

First Order Phase Transition ◽

Definition Of ◽

First Order Phase

Abstract Recent work has shown that certain deformations of the scalar potential in Jackiw-Teitelboim gravity can be written as double-scaled matrix models. However, some of the deformations exhibit an apparent breakdown of unitarity in the form of a negative spectral density at disc order. We show here that the source of the problem is the presence of a multi-valued solution of the leading order matrix model string equation. While for a class of deformations we fix the problem by identifying a first order phase transition, for others we show that the theory is both perturbatively and non-perturbatively inconsistent. Aspects of the phase structure of the deformations are mapped out, using methods known to supply a non-perturbative definition of undeformed JT gravity. Some features are in qualitative agreement with a semi-classical analysis of the phase structure of two-dimensional black holes in these deformed theories.

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Hamiltonian charges in the asymptotically de Sitter spacetimes

Journal of High Energy Physics ◽

10.1007/jhep05(2021)063 ◽

2021 ◽

Vol 2021 (5) ◽

Author(s):

Maciej Kolanowski ◽

Jerzy Lewandowski

Keyword(s):

Phase Space ◽

Initial Data ◽

Exact Solutions ◽

Gravitational Waves ◽

Physical Meaning ◽

De Sitter ◽

Killing Vectors ◽

Asymptotically Flat ◽

Angular Momenta ◽

The One

Abstract We generalize a notion of ‘conserved’ charges given by Wald and Zoupas to the asymptotically de Sitter spacetimes. Surprisingly, our construction is less ambiguous than the one encountered in the asymptotically flat context. An expansion around exact solutions possessing Killing vectors provides their physical meaning. In particular, we discuss a question of how to define energy and angular momenta of gravitational waves propagating on Kottler and Carter backgrounds. We show that obtained expressions have a correct limit as Λ → 0. We also comment on the relation between this approach and the one based on the canonical phase space of initial data at ℐ+.

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