scholarly journals Derivation of the set of the fundamental interactions from first principles

2021 ◽  
Vol 137 (1) ◽  
Author(s):  
Jiri Voltr
Keyword(s):  
Conservation Laws ◽  
Parity Violation ◽  
First Principles ◽  
Weak Decay ◽  
Fundamental Interaction ◽  
Fundamental Interactions ◽  
Fundamental Information ◽  
Information Transfers ◽  
Strong Scattering ◽  
Rule Out

AbstractGlobal conservation laws require the fundamental interactions to be processes which transfer information from one particle to another. Therefore, in order to show what types of interactions may exist, we derive from the very first principles a set of the most fundamental information transfers and their basic properties. Within these information transfers, we identify candidates for gravitational, electromagnetic and strong scattering, and also for weak decay. We do it by taking the characteristic properties of each fundamental interaction, such as confinement or parity violation, and by using them to rule out information transfers without these properties. The found mapping then makes possible to study the information transfers in order to get knowledge about the corresponding fundamental interactions.

Fundamental Interactions of Fe in Silicon: First-Principles Theory

2007 ◽  
Vol 131-133 ◽  
pp. 233-240 ◽  
Author(s):  
Stefan K. Estreicher ◽  
Mahdi Sanati ◽  
N. Gonzalez Szwacki
Keyword(s):  
First Principles ◽  
Activation Energies ◽  
Spin States ◽  
Hydrogen Passivation ◽  
First Principles Calculations ◽  
Native Defects ◽  
Fundamental Interactions ◽  
Recombination Centers

Interstitial iron and iron-acceptor pairs are well studied but undesirable defects in Si as they are strong recombination centers which resist hydrogen passivation. Thermal anneals often result in the precipitation of Fe. Relatively little information is available about the interactions between Fe and native defects or common impurities in Si. We present the results of first-principles calculations of Fe interactions with native defects (vacancy, self-interstitial) and common impurities such as C, O, H, or Fe. The goal is to understand the fundamental chemistry of Fe in Si, identify and characterize the type of complexes that occur. We predict the configurations, charge and spin states, binding and activation energies, and estimate the position of gap levels. The possibility of passivation is discussed.

scholarly journals SEVERE CHALLENGES IN GRAVITY THEORIES

2012 ◽  
Vol 07 ◽  
pp. 219-226
Author(s):  
YUAN K. HA
Keyword(s):  
Statistical Mechanics ◽  
Attractive Force ◽  
Fundamental Interaction ◽  
Quantum Theories ◽  
Fundamental Interactions ◽  
Underlying Theory ◽  
Theories Of Gravity ◽  
Gravity Theories ◽  
Classical Thermodynamics

Gravity is specifically the attractive force between two masses separated at a distance. Is this force a derived or a fundamental interaction? We believe that all fundamental interactions are quantum in nature but a derived interaction may be classical. Severe challenges have appeared in many quantum theories of gravity. None of these theories has thus far attained its goal in quantizing gravity and some have met remarkable defeat. We are led to ponder whether gravitation is intrinsically classical and that there would exist a deeper and structurally different underlying theory which would give rise to classical gravitation, in the sense that statistical mechanics, quantum or classical, provides the underlying theory of classical thermodynamics.

A First-Principles Calculation of the Resistivity and Thermopower in Strong-Scattering Alloys

1988 ◽  
Vol 141 ◽  
Author(s):  
Randall H. Brown ◽  
Philip B. Allen ◽  
Donald M. Nicholson ◽  
William H. Butler
Keyword(s):  
First Principles ◽  
Statistical Error ◽  
Mean Free Path ◽  
Localized States ◽  
First Principles Calculation ◽  
Disordered Alloys ◽  
Alloy Disorder ◽  
Electron Mean Free Path ◽  
Strong Scattering ◽  
Temperature Resistivity

AbstractWe investigate the concentration and short-range order dependence of the zero-temperature resistivity and thermopower for substitutionally disordered alloys from a first-principles approach. The alloy disorder is simulated by calculating the electronic structure of a large supercell (typically 200–250 atoms) with periodic boundary conditions. For the strong-scattering alloys we consider, the electron mean-free path is much less than the supercell dimension, causing artificial effects of periodicity to be negligible. In spite of strong scattering, there is no evidence for localized states near EF. The resistivity and thermopower are averaged over several configurations resulting in statistical error bounds of approximately ±10%. The concentration-dependent resistivity of substitutional V1−xAlx alloys agree well with Korringa-Kohn-Rostoker coherent potential approximation (KKR CPA) calculations. This confirms the accuracy of KKR CPA theory.

scholarly journals Parity violation in Poincaré gauge gravity

2020 ◽  
pp. 2150022 ◽  
Author(s):  
Yuri N. Obukhov
Keyword(s):  
Field Equation ◽  
Gauge Theory ◽  
Conservation Laws ◽  
Parity Violation ◽  
Einstein Field Equation ◽  
Effective Energy ◽  
Natural Extensions ◽  
Cartan Theory ◽  
Gauge Gravity ◽  
Gauge Theory Of Gravity

We analyze the parity violation issue in the Poincaré gauge theory of gravity for the two classes of models which are built as natural extensions of the Einstein–Cartan theory. The conservation laws of the matter currents are revisited and we clarify the derivation of the effective Einstein field equation and the structure of the effective energy–momentum current for arbitrary matter sources.

A rapid method for the direct identification of paramyxovirus in canine CSF by ultracentrifugation and negative staining as a rule out for distemper

1990 ◽  
Vol 48 (3) ◽  
pp. 594-595
Author(s):  
W.L. Steffens ◽  
M.B. Ard ◽  
C.E. Greene ◽  
A. Jaggy
Keyword(s):  
Subacute Sclerosing Panencephalitis ◽  
Clinical Signs ◽  
Viral Disease ◽  
Etiologic Agent ◽  
Mucosal Inflammation ◽  
Worldwide Distribution ◽  
Negative Stain ◽  
Viral Particles ◽  
Systemic Manifestations ◽  
Rule Out

Canine distemper is a multisystemic contagious viral disease having a worldwide distribution, a high mortality rate, and significant central neurologic system (CNS) complications. In its systemic manifestations, it is often presumptively diagnosed on the basis of clinical signs and history. Few definitive antemortem diagnostic tests exist, and most are limited to the detection of viral antigen by immunofluorescence techniques on tissues or cytologic specimens or high immunoglobulin levels in CSF (cerebrospinal fluid). Diagnosis of CNS distemper is often unreliable due to the relatively low cell count in CSF (<50 cells/μl) and the binding of blocking immunoglobulins in CSF to cell surfaces. A more reliable and definitive test might be possible utilizing direct morphologic detection of the etiologic agent. Distemper is the canine equivalent of human measles, in that both involve a closely related member of the Paramyxoviridae, both produce mucosal inflammation, and may produce CNS complications. In humans, diagnosis of measles-induced subacute sclerosing panencephalitis is through negative stain identification of whole or incomplete viral particles in patient CSF.

Impairment Questions and Answers

1999 ◽  
Vol 4 (4) ◽  
pp. 4-4
Keyword(s):  
Symptom Validity ◽  
Validity Testing ◽  
Symptom Validity Testing ◽  
Negative Results ◽  
Tunnel Vision ◽  
Questions And Answers ◽  
Blurry Vision ◽  
Fatigue Evaluation ◽  
Choice Testing ◽  
Rule Out

Abstract Symptom validity testing, also known as forced-choice testing, is a way to assess the validity of sensory and memory deficits, including tactile anesthesias, paresthesias, blindness, color blindness, tunnel vision, blurry vision, and deafness—the common feature of which is a claimed inability to perceive or remember a sensory signal. Symptom validity testing comprises two elements: A specific ability is assessed by presenting a large number of items in a multiple-choice format, and then the examinee's performance is compared with the statistical likelihood of success based on chance alone. Scoring below a norm can be explained in many different ways (eg, fatigue, evaluation anxiety, limited intelligence, and so on), but scoring below the probabilities of chance alone most likely indicates deliberate deception. The positive predictive value of the symptom validity technique likely is quite high because there is no alternative explanation to deliberate distortion when performance is below the probability of chance. The sensitivity of this technique is not likely to be good because, as with a thermometer, positive findings indicate that a problem is present, but negative results do not rule out a problem. Although a compelling conclusion is that the examinee who scores below probabilities is deliberately motivated to perform poorly, malingering must be concluded from the total clinical context.

Case Exercise: Toxic Exposure-Related Illness: Causation, Diagnosis, and Permanent Impairment

2007 ◽  
Vol 12 (2) ◽  
pp. 4-8
Author(s):  
Frederick Fung
Keyword(s):  
Concentration Level ◽  
Treatment Plan ◽  
Toxic Exposure ◽  
Dose Response Relationship ◽  
Specialty Board ◽  
History Of ◽  
Subjective Complaints ◽  
Based Medicine ◽  
Illness Causation ◽  
Rule Out

Abstract A diagnosis of toxic-related injury/illness requires a consideration of the illness related to the toxic exposure, including diagnosis, causation, and permanent impairment; these are best performed by a physician who is certified by a specialty board certified by the American Board of Preventive Medicine. The patient must have a history of symptoms consistent with the exposure and disease at issue. In order to diagnose the presence of a specific disease, the examiner must find subjective complaints that are consistent with the objective findings, and both the subjective complaints and objective findings must be consistent with the disease that is postulated. Exposure to a specific potentially causative agent at a defined concentration level must be documented and must be sufficient to induce a particular pathology in order to establish a diagnosis. Differential diagnoses must be entertained in order to rule out other potential causes, including psychological etiology. Furthermore, the identified exposure at the defined concentration level must be capable of causing the diagnosis being postulated before the examiner can conclude that there has been a cause-and-effect relationship between the exposure and the disease (dose-response relationship). The evaluator's opinion should make biological and epidemiological sense. The treatment plan and prognosis should be consistent with evidence-based medicine, and the rating of impairment must be based on objective findings in involved systems.

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