scholarly journals QUIESCENT COSMOLOGY AND THE FINAL STATE OF THE UNIVERSE

2008 ◽  
Vol 17 (03n04) ◽  
pp. 571-576 ◽  
Author(s):  
PHILIPP A. HÖHN ◽  
SUSAN M. SCOTT
Keyword(s):  
Mathematical Formulation ◽  
Primary Objective ◽  
Mathematical Framework ◽  
Final States ◽  
Structure And Properties ◽  
Initial State ◽  
Final State ◽  
Future Singularity ◽  
Definition Of ◽  
The Universe

It has long been a primary objective of cosmology to understand the apparent isotropy in our universe and to provide a mathematical formulation for its evolution. A promising school of thought for its explanation is quiescent cosmology, which already possesses a mathematical framework, namely the definition of an isotropic singularity, but only for the initial state of the universe. A complementary framework is necessary in order to also describe possible final states of the universe. Our new definitions of an anisotropic future endless universe and an anisotropic future singularity, whose structure and properties differ significantly from those of the isotropic singularity, offer a promising realization for this framework. The combination of the three definitions together may then provides the first complete formalization of the quiescent cosmology concept.

scholarly journals Observation of Ionization of Laser Excited Atoms by Synchrotron Radiation

1984 ◽  
Vol 86 ◽  
pp. 128-131
Author(s):  
J.M. Bizau ◽  
F. Wuilleumier ◽  
P. Gerard ◽  
P. Dhez ◽  
B. Carré ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Photoelectron Spectroscopy ◽  
Oscillator Strengths ◽  
Final States ◽  
Initial State ◽  
Final State ◽  
Core Electron ◽  
Output Mirror ◽  
Initial States ◽  
A New Technique

We have begun a program to measure oscillator strengths of autoionizing resonances that result from a transition in the VUV between a laser excited initial state and a final state in which a core electron is promoted. These measurements demonstrate a new technique to combine synchrotron radiation, laser pumping, and photoelectron spectroscopy.Measurements of the energy positions of autoionizing resonances have been honed to a fine art over the past 50 years. Total cross section measurements and the parameters that describe autoionizing resonances have been determined. Most of these studies have been made from the dipole allowed ground state. Recently autoionizing resonances have been observed from excited initial states and from ion initial states. We have heard several talks, at this meeting which described some of this type of research. In the measurements to be described in this paper, laser radiation is combined with synchrotron radiation, as shown schematicaly in Figure 1, to study the photoionization from excited initial states to continuum final states or to autoionizing final states. Continuum radiation from the Aneau de Collisions d’Orsay (ACO), which is installed at the Universite de Paris-Sud, in Orsay France, is monochromatized by a toroidal grating monochromator (TGM) and is focused by a toroidal output mirror on to a weakly collimated sodium beam emanating from a furnace mounted on the axis of a cylinderical mirror analyzer (CMA). This electron spectrometer is used to study the kinetic energy distribution of the ejected photoelectrons produced by the interaction of the photon beam with the focused synchrotron radiation.

scholarly journals Patterns and paschen-back analogue in the stark-effect for neon

1929 ◽  
Vol 123 (791) ◽  
pp. 80-103 ◽  
Keyword(s):  
Quantum Number ◽  
Stark Effect ◽  
Selection Rule ◽  
Theoretical Calculations ◽  
Zeeman Effect ◽  
Final States ◽  
Outer Electron ◽  
Initial State ◽  
Final State ◽  
Left Handed

While the Stark-effect has not been studied so extensively as the Zeeman-effect, either in the experiments or in their interpretations, many of the more prominent features have been observed and have received adequate explanation on the quantum theory. Among these may be mentioned the patterns characteristic of the different series in the singlet system of parhelium. The variety of observed patterns in the Stark-effect, as contrasted with the normal Zeeman-effect found for all series of this system, arises from a differential action of the external electric field on the initial and final states, and a breaking down of the usual selection rule for the azimuthal quantum number. Some simplification is brought about, however, by the fact that only the absolute value of the quantum number m has any meaning in the interpretation of these photographs, since the action of the field is the same for right or left-handed motion of the outer electron in its orbit. This results in asymmetrical patterns for all the lines. The number of components observed in the patterns of individual lines of parhelium is in accord with the theoretical view that the vector j (here equal to l ) is resolved along the direction of the applied field to give the integral m values ranging from - j to + j , and that the usual selection rule holds for m . The displacements and intensities are in excellent agreement with the theoretical calculations based on the perturbation theory of quantum mechanics. The spacing of the sub-levels identified by ± m in the initial state is decidedly irregular in the Stark-effect as compared with the normal Zeeman-effect, where the displacements are proportional to m . The Zeeman order of the levels is usually reversed, in fact, and the spacing is uneven. Displacements in the final state are theoretically very small, and have not been observed with certainty. In the Stark-effect for orthohelium (triplet system) the same group of patterns was observed. An explanation of these observations, which is slightly less satisfactory than that obtained with parhelium, has been made by similar methods, neglecting the electron spin. Thus the m values were again given ranges determined in each case by the l of the outer electron, and not by the j for the whole atom. Most of the plates failed to reveal any of the fine structure of the normal orthohelium spectrum.

scholarly journals EIGENMODE OF THE DECISION-BY-MAJORITY PROCESS IN COMPLEX NETWORKS

2008 ◽  
Vol 11 (04) ◽  
pp. 565-579
Author(s):  
MAKOTO UCHIDA ◽  
SUSUMU SHIRAYAMA
Keyword(s):  
Complex Networks ◽  
Network Models ◽  
Ising Models ◽  
Final States ◽  
Zero Temperature ◽  
Opinion Formation ◽  
Initial State ◽  
Final State ◽  
Numerical Studies ◽  
Eigenmode Analysis

The nature of the dynamics of opinion formation or zero-temperature Ising models modeled as a decision-by-majority process in complex networks is investigated using eigenmode analysis. The Hamiltonian of the system is defined and estimated by eigenvectors of the adjacency matrix constructed from several network models. The rule of the process is assumed to be equivalent to the minimization of the Hamiltonian. The initial and final states of the dynamics are decomposed on the basis of the eigenvectors. The process and the eigenmodes are analyzed by numerical studies. We show that the magnitude of the coefficient for the largest eigenvector at the initial states is the key determinant for the resulting dynamics. We thus prove that the final state of the dynamics can be estimated by the eigenmodes of the initial state.

scholarly journals Transverse Single Spin Asymmetries of Forward π0 and Jet-like Events in s = 500 GeV Polarized Proton Collisions at STAR

2016 ◽  
Vol 40 ◽  
pp. 1660037 ◽  
Author(s):  
Yuxi Pan
Keyword(s):  
Final States ◽  
High Transverse Momentum ◽  
Initial State ◽  
Final State ◽  
Spin Asymmetries ◽  
Proton Collisions ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Polarized Proton ◽  
State Models

The large transverse single spin asymmetries (SSA) of high [Formula: see text] inclusive hadrons produced in polarized proton collisions are usually explained by means of collinear twist-3 multi-parton correlations. In this picture these asymmetries can originate from initial-state twist-3 parton distributions in the polarized proton and/or through the coupling between proton transversity and twist-3 fragmentation functions. The measurement of SSA for forward inclusive hadrons produced in [Formula: see text] collisions out to high transverse momentum helps to examine the validity and interplay of these initial- and final-state models. These models can be further explored by investigating the dependence of the SSA on event topologies. We present our latest status on the measurement of SSA for forward inclusive [Formula: see text] detected within [Formula: see text] in [Formula: see text] = 500 GeV [Formula: see text] collisions as well as its dependence on event topologies. We will also present our analysis of Sivers and Collins asymmetries for forward jet-like events consisting of multi-photon final states. The measurements are based on the data taken in 2011 with integrated luminosity [Formula: see text] 22 [Formula: see text].

Chemical Thermodynamics

2009 ◽  
Author(s):  
Christopher O. Oriakhi
Keyword(s):  
Internal Energy ◽  
Thermodynamic Quantity ◽  
Energy Change ◽  
Chemical Thermodynamics ◽  
State Function ◽  
Initial State ◽  
Final State ◽  
Spontaneous Process ◽  
The Law ◽  
The Universe

Chemical thermodynamics is the study of the energy changes and transfers associated with chemical and physical transformations. Energy is the ability to do work or to transfer heat. A spontaneous process is one that can occur on its own without any external influence. A spontaneous process always moves a system in the direction of equilibrium. When a process or reaction cannot occur under the prescribed conditions, it is nonspontaneous. The reverse of a spontaneous process or reaction is always nonspontaneous. Heat (q) is the energy transferred between a system and its surroundings due to a temperature difference. Work (w) is the energy change when a force (F) moves an object through a distance (d). Thus. . . W = F ×d. . . . A system is a specified part of the universe (e.g., a sample or a reaction mixture we are studying). Everything outside the system is referred to as the surroundings. The universe is the system plus the surroundings. A state function is a thermodynamic quantity that defines the present state or condition of the system. Changes in state function quantities are independent of the path (or process) used to arrive at the final state from the initial state. Examples of state functions include enthalpy change (ΔH), entropy change, (ΔS) and free energy change, (ΔG). The internal energy of a system is the sum of the kinetic and potential energies of the particles making up the system. While it is not possible to determine the absolute internal energy of a system, we can easily measure changes in internal energy (which correspond to energy given off or absorbed by the system). The change in internal energy, . . . ΔE, is: ΔE = Efinal –Einitial. . . . The first law of thermodynamics, also called the law of conservation of energy, states that the total amount of energy in the universe is constant, that is, energy can neither be created nor destroyed. It can only be converted from one form into another. In mathematical terms, the law states that the change in internal energy of a system, ΔE, equals q+w. That is,. . . ΔE = q+w. . . In other words, the change in E is equal to the heat absorbed (or emitted) by the system, plus work done on (or by) the system.

A simple all-time model for the birth, big bang, and death of the universe

2017 ◽  
Vol 26 (12) ◽  
pp. 1743014 ◽  
Author(s):  
Arthur E. Fischer
Keyword(s):  
Line Element ◽  
De Novo ◽  
Big Bang ◽  
De Sitter ◽  
Initial State ◽  
Final State ◽  
Cosmological Singularity ◽  
State Formula ◽  
The Big Bang ◽  
The Universe

We model the standard [Formula: see text]CDM model of the universe by the spatially flat FLRW line element [Formula: see text] which we extend for all time [Formula: see text]. Although there is a cosmological singularity at the big bang [Formula: see text], since the spatial part of the metric collapses to zero, nevertheless, this line element is defined for all time [Formula: see text], is [Formula: see text] for all [Formula: see text], is [Formula: see text] differentiable at [Formula: see text], and is non-degenerate and solves Friedmann’s equation for all [Formula: see text]. Thus, we can use this extended line element to model the universe from its past-asymptotic initial state [Formula: see text] at [Formula: see text], through the big bang at [Formula: see text], and onward to its future-asymptotic final state [Formula: see text] at [Formula: see text]. Since in this model the universe existed before the big bang, we conclude that (1) the universe was not created de novo at the big bang and (2) cosmological singularities such as black holes or the big bang itself need not be an end to spacetime. Our model shows that the universe was asymptotically created de novo out of nothing at [Formula: see text] from an unstable vacuum negative half de Sitter [Formula: see text] initial state and then dies asymptotically at [Formula: see text] as the stable positive half de Sitter [Formula: see text] final state. Since the de Sitter states are vacuum matter states, our model shows that the universe was created from nothing at [Formula: see text] and dies at [Formula: see text] to nothing.

scholarly journals TWO NONCOMMUTATIVE PARAMETERS AND REGULAR COSMOLOGICAL PHASE TRANSITION IN THE SEMICLASSICAL DILATON COSMOLOGY

2008 ◽  
Vol 23 (15) ◽  
pp. 1079-1091 ◽  
Author(s):  
WONTAE KIM ◽  
EDWIN J. SON
Keyword(s):  
Phase Transition ◽  
Equations Of Motion ◽  
Accelerated Expansion ◽  
Dilaton Gravity ◽  
Initial State ◽  
Future Singularity ◽  
Flat Spacetime ◽  
Modified Equations ◽  
Expansion Of The Universe ◽  
The Universe

We study cosmological phase transitions from modified equations of motion by introducing two noncommutative parameters in the Poisson brackets, which describes the initial- and future-singularity-free phase transition in the soluble semiclassical dilaton gravity with a nonvanishing cosmological constant. Accelerated expansion and decelerated expansion appear alternatively, where the model contains the second accelerated expansion. The final stage of the universe approaches the flat spacetime independent of the initial state of the curvature scalar as long as the product of the two noncommutative parameters is less than one. Finally, we show that the initial-singularity-free condition is related to the second accelerated expansion of the universe.

scholarly journals A Fit to the Available e+e-→Λc+Λ-c- cross Section Data Nearby Production Threshold by Means of a Strong Correction to the Coulomb Enhancement Factor

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 436
Author(s):  
Antonio Amoroso ◽  
Stefano Bagnasco ◽  
Rinaldo Baldini Ferroli ◽  
Ilaria Balossino ◽  
Monica Bertani ◽  
...  
Keyword(s):  
Cross Section ◽  
Enhancement Factor ◽  
Final States ◽  
Cross Section Data ◽  
Initial State ◽  
Final State ◽  
Production Threshold ◽  
Section Data ◽  
State Radiation ◽  
Radiation Technique

There are two available sets of data on the e+e−→Λc+Λ¯c− cross section at energies close to the production threshold, collected by the Belle and by the BESIII Collaborations. The measurement of the former, performed by means of the initial state radiation technique, is compatible with the presence of a resonance, called ψ(4660), observed also in other final states. On the contrary, the latter is measured an almost flat and hence non-resonant cross section in the energy region just above the production threshold, but the data stop before the possible rise in the cross section for the resonant production. We propose an effective model to describe the behavior of the data near this threshold, which is based on a Coulomb-like enhancement factor due to the strong interaction among the final state particles. In the framework of this model, it is possible to describe both datasets.

scholarly journals Dual subtractions

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Renato Maria Prisco ◽  
Francesco Tramontano
Keyword(s):  
Field Theory ◽  
Quantum Field ◽  
Matrix Elements ◽  
Leading Order ◽  
Initial State ◽  
Final State ◽  
Dual Representation ◽  
Subtraction Scheme ◽  
Theoretical Predictions ◽  
Perturbative Quantum

Abstract We propose a novel local subtraction scheme for the computation of Next-to-Leading Order contributions to theoretical predictions for scattering processes in perturbative Quantum Field Theory. With respect to well known schemes proposed since many years that build upon the analysis of the real radiation matrix elements, our construction starts from the loop diagrams and exploits their dual representation. Our scheme implements exact phase space factorization, handles final state as well as initial state singularities and is suitable for both massless and massive particles.

scholarly journals Local modal participation analysis of nonlinear systems using Poincaré linearization

2019 ◽  
Vol 99 (1) ◽  
pp. 803-811 ◽  
Author(s):  
Boumediene Hamzi ◽  
Eyad H. Abed
Keyword(s):  
Nonlinear Systems ◽  
Autonomous Systems ◽  
Analytical Formula ◽  
Linear Case ◽  
Local Mode ◽  
Initial Condition ◽  
Initial State ◽  
State Participation ◽  
Symmetry Assumption ◽  
Definition Of

AbstractThe paper studies an extension to nonlinear systems of a recently proposed approach to the definition of modal participation factors. A definition is given for local mode-in-state participation factors for smooth nonlinear autonomous systems. While the definition is general, the resulting measures depend on the assumed uncertainty law governing the system initial condition, as in the linear case. The work follows Hashlamoun et al. (IEEE Trans Autom Control 54(7):1439–1449 2009) in taking a mathematical expectation (or set-theoretic average) of a modal contribution measure over an uncertain set of system initial state. Poincaré linearization is used to replace the nonlinear system with a locally equivalent linear system. It is found that under a symmetry assumption on the distribution of the initial state, the tractable calculation and analytical formula for mode-in-state participation factors found for the linear case persists to the nonlinear setting. This paper is dedicated to the memory of Professor Ali H. Nayfeh.

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