scholarly journals Efficient treatment of the high-frequency tail of the self-energy function and its relevance for multiorbital models

2012 ◽  
Vol 85 (11) ◽  
Author(s):  
Gang Li ◽  
Werner Hanke
Keyword(s):  
Energy Function ◽  
High Frequency ◽  
The Self ◽  
Efficient Treatment ◽  
Self Energy

NEGF-based models for dephasing in quantum transport

2017 ◽  
Author(s):  
Roksana Golizadeh-Mojarad ◽  
Supriyo Datta
Keyword(s):  
Quantum Transport ◽  
Wide Class ◽  
Energy Function ◽  
The Self ◽  
Self Energy ◽  
Different Types ◽  
Momentum Relaxation ◽  
Spin Devices ◽  
Non Equilibrium Green’S Function ◽  
General Method

This article describes the use of NEGF-based models for elastic dephasing in quantum transport. The non-equilibrium Green's function (NEGF) method provides a rigorous prescription for including any kind of dephasing mechanisms to any order starting from a microscopic Hamiltonian through an appropriate choice of the self-energy function. The article first introduces the general approach to quantum transport that provides a general method for modelling a wide class of nanotransistor and spin devices. It then discusses the effect of different types of dephasing on momentum and spin relaxation before considering three simple phenomenological choices of the self-energy function that allows one to incorporate spin, phase and momentum relaxation independently. It also looks at an example that takes into account these three types of dephasing mechanisms: the ‘spin-Hall’ effect.

scholarly journals Singular behavior of the photon density of states and the self-energy function of an electron in photonic crystal

2014 ◽  
Vol 560 ◽  
pp. 012007
Author(s):  
R Kh Gainutdinov ◽  
M A Khamadeev ◽  
D N Avramenko ◽  
K A Ziyatdinova ◽  
M Kh Salakhov
Keyword(s):  
Photonic Crystal ◽  
Density Of States ◽  
Energy Function ◽  
The Self ◽  
Photon Density ◽  
Singular Behavior ◽  
Self Energy

scholarly journals Opacity from Loops in AdS

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Alexandria Costantino ◽  
Sylvain Fichet
Keyword(s):  
Imaginary Part ◽  
Quantum Dynamics ◽  
Model Building ◽  
Asymptotic Properties ◽  
The Self ◽  
Effective Theory ◽  
Self Energy ◽  
Higher Dimensional ◽  
Timelike Region ◽  
Spectral Representations

Abstract We investigate how quantum dynamics affects the propagation of a scalar field in Lorentzian AdS. We work in momentum space, in which the propagator admits two spectral representations (denoted “conformal” and “momentum”) in addition to a closed-form one, and all have a simple split structure. Focusing on scalar bubbles, we compute the imaginary part of the self-energy ImΠ in the three representations, which involves the evaluation of seemingly very different objects. We explicitly prove their equivalence in any dimension, and derive some elementary and asymptotic properties of ImΠ.Using a WKB-like approach in the timelike region, we evaluate the propagator dressed with the imaginary part of the self-energy. We find that the dressing from loops exponentially dampens the propagator when one of the endpoints is in the IR region, rendering this region opaque to propagation. This suppression may have implications for field-theoretical model-building in AdS. We argue that in the effective theory (EFT) paradigm, opacity of the IR region induced by higher dimensional operators censors the region of EFT breakdown. This confirms earlier expectations from the literature. Specializing to AdS5, we determine a universal contribution to opacity from gravity.

scholarly journals Classical gravitational self-energy from double copy

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Gabriel Luz Almeida ◽  
Stefano Foffa ◽  
Riccardo Sturani
Keyword(s):  
Gravitational Field ◽  
Binary System ◽  
The Self ◽  
Gravitational Coupling ◽  
Leading Order ◽  
Body System ◽  
Self Energy ◽  
Composite Systems ◽  
Body Dynamics ◽  
Double Copy

Abstract We apply the classical double copy to the calculation of self-energy of composite systems with multipolar coupling to gravitational field, obtaining next-to-leading order results in the gravitational coupling GN by generalizing color to kinematics replacement rules known in literature. When applied to the multipolar description of the two-body system, the self-energy diagrams studied in this work correspond to tail processes, whose physical interpretation is of radiation being emitted by the non-relativistic source, scattered by the curvature generated by the binary system and then re-absorbed by the same source. These processes contribute to the conservative two-body dynamics and the present work represents a decisive step towards the systematic use of double copy within the multipolar post-Minkowskian expansion.

scholarly journals The self-energy of a confined quark

1983 ◽  
Vol 131 (4-6) ◽  
pp. 445-449 ◽  
Author(s):  
S. Goldhaber ◽  
T.H. Hansson ◽  
R.L. Jaffe
Keyword(s):  
The Self ◽  
Self Energy

A NEW HAMILTONIAN OF INTERACTION FOR FERMIONS

2005 ◽  
Vol 19 (13n14) ◽  
pp. 669-681 ◽  
Author(s):  
ANDREI DOLOCAN ◽  
VOICU OCTAVIAN DOLOCAN ◽  
VOICU DOLOCAN
Keyword(s):  
Interaction Energy ◽  
The Self ◽  
Lagrangian Formalism ◽  
Expectation Values ◽  
Boson System ◽  
Self Energy ◽  
Fermion Gas

Using the Lagrangian formalism we attempt to introduce a new Hamiltonian for fermions. On this basis we have evaluated the expectation values for the interaction energy between fermions via bosons. The interaction energy between two fermions via phonons becomes attractive in a degenerate fermion-gas. The interaction energy between two fermions via photons appears to be attractive in certain conditions. The self-energy of the fermion + boson system, e.g. polaron and polariton, was evaluated.

Hearing Loss and Hearing Handicap in Users of Recreational Firearms

2002 ◽  
Vol 13 (03) ◽  
pp. 160-168 ◽  
Author(s):  
Michael Stewart ◽  
Rebecca Pankiw ◽  
Mark E. Lehman ◽  
Thomas H. Simpson
Keyword(s):  
Hearing Loss ◽  
American Academy ◽  
High Frequency ◽  
Pure Tone ◽  
Occupational Safety ◽  
Occupational Safety And Health ◽  
Gender Effects ◽  
The Self ◽  
Safety And Health ◽  
Hearing Handicap

This investigation sought to establish the prevalence of hearing loss and hearing handicap in a population of 232 recreational firearm users. Hearing handicap was calculated based on four methods using pure-tone threshold data from the American Academy of Ophthalmology and Otolaryngology, American Academy of Otolaryngology-Head and Neck Surgery, National Institute of Occupational Safety and Health, and American Speech-Language and Hearing Association in addition to the self-report Hearing Handicap Inventory for Adults-Screener (HHIA-S). Subjects (45 female and 187 male) ranging in age from 13 to 77 years (mean = 40 years, SD = 15.1) completed a short questionnaire regarding demographics and shooting practices followed by pure-tone air audiometry at Occupational Safety and Health Administration test frequencies of 500 to 6000 Hz. A total of 177 who exhibited varying degrees of hearing loss also received a face-to-face administration of the HHIA-S. Audiometric and HHIA-S results revealed that both high-frequency hearing loss and hearing handicap varied significantly as functions of age and occupation. Significant gender effects were observed audiometrically but not as a function of hearing handicap. HHIA-S scores varied significantly as a function of high-frequency (1000–4000 Hz) hearing loss. Correlation coefficients between the four different pure-tone methods of calculating hearing handicap and the self-reported HHIA-S were highest for pure-tone methods that do not employ 500 Hz in the calculation.

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