scholarly journals Summary Talk : Multi-Wavelength Sky Surveys

1998 ◽  
Vol 179 ◽  
pp. 493-499
Author(s):  
O. Lahav
Keyword(s):  
Gamma Rays ◽  
Dimensional Space ◽  
Instrument Design ◽  
List Type ◽  
Type Number ◽  
Sky Surveys ◽  
3 Dimensional ◽  
Multi Wavelength ◽  
The Universe ◽  
Summary Talk

An astronomer's career can be viewed in a 3-dimensional space where the (nearly orthogonal) axes are : – the objects of interest (from planets to the Universe),– techniques (from instrument design to analytic calculations),– the wavelength (from the radio to gamma rays).

Derivations Tangential to Compact Group Actions: Spectral Conditions in the Weak Closure

1985 ◽  
Vol 37 (1) ◽  
pp. 160-192 ◽  
Author(s):  
Ola Bratteli ◽  
Frederick M. Goodman
Keyword(s):  
Finite Elements ◽  
Common Core ◽  
Dimensional Space ◽  
List Type ◽  
Finite Dimensional Space ◽  
Type Number ◽  
Compact Lie Group ◽  
Parameter Group ◽  
Finite Dimensional ◽  
Image Position

Let G be a compact Lie group and a an action of G on a C*-algebra as *-automorphisms. Let denote the set of G-finite elements for this action, i.e., the set of those such that the orbit {αg(x):g ∊ G} spans a finite dimensional space. is a common core for all the *-derivations generating one-parameter subgroups of the action α. Now let δ be a *-derivation with domain such that Let us pose the following two problems:Is δ closable, and is the closure of δ the generator of a strongly continuous one-parameter group of *-automorphisms?If is simple or prime, under what conditions does δ have a decompositionwhere is the generator of a one-parameter subgroup of α(G) and is a bounded, or approximately bounded derivation?

scholarly journals Solar X radiation

1965 ◽  
Vol 23 ◽  
pp. 45-52 ◽  
Author(s):  
C. de Jager
Keyword(s):  
Electromagnetic Radiation ◽  
Gamma Rays ◽  
Electronic Transitions ◽  
List Type ◽  
X Rays ◽  
Type Number ◽  
X Ray ◽  
Image Position ◽  
Electron Shells

X-ray bursts are defined as electromagnetic radiation originating from electronic transitions involving the lowest electron shells; gamma rays are of nuclear origin. Solar gamma rays have not yet been discovered.According to the origin we have : 1.Quasi thermal X-rays, emitted by (a) the quiet corona, (b) the activity centers without flares, and (c) the X-ray flares.2.Non-thermal X-ray bursts; these are always associated with flares.The following subdivision is suggested for flare-associated bursts :

scholarly journals On the geometry of the space-time and motion of the spinning bodies

Open Physics ◽  
2013 ◽  
Vol 11 (3) ◽  
Author(s):  
Kostadin Trenčevski
Keyword(s):  
Dimensional Space ◽  
Space Time ◽  
Alternative Theory ◽  
Gravitational Acceleration ◽  
3 Dimensional ◽  
Classical Formulation ◽  
Time And Motion ◽  
Spinning Bodies ◽  
Spatial Rotations ◽  
The Universe

AbstractIn this paper an alternative theory about space-time is given. First some preliminaries about 3-dimensional time and the reasons for its introduction are presented. Alongside the 3-dimensional space (S) the 3-dimensional space of spatial rotations (SR) is considered independently from the 3-dimensional space. Then it is given a model of the universe, based on the Lie groups of real and complex orthogonal 3 × 3 matrices in this 3+3+3-dimensional space. Special attention is dedicated for introduction and study of the space S × SR, which appears to be isomorphic to SO(3,ℝ) × SO(3,ℝ) or S 3 × S 3. The influence of the gravitational acceleration to the spinning bodies is considered. Some important applications of these results about spinning bodies are given, which naturally lead to violation of Newton’s third law in its classical formulation. The precession of the spinning axis is also considered.

Radio-frequency emission from supernova ejecta

1967 ◽  
Vol 31 ◽  
pp. 429-430
Author(s):  
S. A. Colgate
Keyword(s):  
Background Radiation ◽  
Dominant Role ◽  
Black Body ◽  
Short Wave ◽  
List Type ◽  
Type Number ◽  
Thermal Radio Emission ◽  
Wave Emission ◽  
Stellar Sources ◽  
The Universe

A new mechanism is proposed for non-thermal radio emission, which depends upon the scattering of photons within an unstable counter-streaming plasma. This mechanism may play a dominant role in several phenomena:(i)the short-wave emission from quasi-stellar sources;(ii)the emission from symmetric supernova nebulae in the early stages of the nebular expansion;(iii)maintenance or modification of the 3 °K black-body background radiation of the Universe.

New Three-Dimensional Algebraic Reconstruction Techniques (Art)

1971 ◽  
Vol 29 ◽  
pp. 82-83 ◽  
Author(s):  
Richard Gordon ◽  
Robert Bender
Keyword(s):  
Three Dimensional ◽  
Fourier Method ◽  
List Type ◽  
Type Number ◽  
Data Set ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Algebraic Reconstruction Techniques ◽  
Electron Microscope Data ◽  
Algebraic Reconstruction

Algebraic reconstruction techniques (ART) for 3-dimensional reconstruction from electron microscope data have been developed and implemented in this laboratory. These methods are an alternitive to the Fourier method of de Rosier and Klug and have several advantages over it, such as:relatively few views are required (about 6-12)limited angular ranges give useful reconstructions (+/-30°)no presumption of symmetry is necessary for facile implementingcomputation is fasterthe computation is stable in the presence of noiseThe dimensionality of the problem may be reduced from three to two by tilts about a single axis, so that planes perpendicular to the axis of tilt are independent of each other. This is not absolutely necessary, but is by far the most tractable mode computationally. A typical input data set, then, consists of m≥6 photos of the same region of the specimen at several known angles of tilt about the same axis. In general the direction of the tilt axis is not known.

scholarly journals The Hot Universe: An Overview

1998 ◽  
Vol 188 ◽  
pp. 3-6
Author(s):  
Y. Tanaka
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
Comprehensive Understanding ◽  
High Energy Astrophysics ◽  
X Ray ◽  
Multi Wavelength ◽  
The Universe

The universe contains an extremely wide variety of temperature structures from 3K to 1 billion K and even beyond. This symposium focuses on the hot part of the universe. The “hot universe” is by far the best place to study high-energy astrophysics. In this overview, I shall be based mainly on the results in the X-ray band that best manifests the hot universe. However, needless to say that multi-wavelength investigations, from radio, infrared through gamma-rays, are essential for comprehensive understanding.

scholarly journals The Problem of the Redshifts

1983 ◽  
Vol 104 ◽  
pp. 65-71
Author(s):  
Geoffrey Burbidge
Keyword(s):  
Statistical Information ◽  
List Type ◽  
Type Number ◽  
Expansion Of The Universe ◽  
The Universe

It is my intention in this brief paper to present once again some of the evidence which appears to show that a major contribution to the redshifts of QSOs and perhaps some galaxies is not associated with the expansion of the universe. The evidence continues to grow and it is of four kinds: (a)Evidence concerning galaxies with discrepant redshifts.(b)Connections between QSOs and galaxies.(c)Statistical information concerning the association of QSOs with galaxies.(d)Individual and very striking examples of pairings between QSOs and bright galaxies.

J. Howard Sobel on the Kalam Cosmological Argument

2006 ◽  
Vol 36 (4) ◽  
pp. 565-584 ◽  
Author(s):  
William Lane Craig
Keyword(s):  
Ab Initio ◽  
Empirical Evidence ◽  
List Type ◽  
Cosmological Argument ◽  
Type Number ◽  
The Past ◽  
Kalam Cosmological Argument ◽  
Kalām Cosmological Argument ◽  
Physical Cosmology ◽  
The Universe

IntroductionJ. Howard Sobel devotes seventy pages of his wide-ranging analysis of theistic arguments to a critique of the cosmological argument. The focus of that critique falls on the argument a contingentia mundi; but he also offers in passing some criticisms of the argument ab initio mundi, or the kalam cosmological argument.Sobel provides the following Statement of the argument:Everything that begins to exist has a cause of its existence.The universe began to exist.Therefore, the universe has a cause of its existence [that did not begin to exist].Sobel will accept the causal premiss (1) only if ‘begins to exist’ means ‘has a first instant of its existence,’ and he disputes the arguments and evidence for (2).Traditional proponents of the kalam argument sought to justify (2) by means of philosophical arguments against the infinity of the past, while contemporary interest in the argument arises from the empirical evidence of physical cosmology for the truth of (2).

Solar Corona Investigation by the Coronal Line Photometer at Lomnický Peak

1994 ◽  
Vol 144 ◽  
pp. 431-434
Author(s):  
M. Minarovjech ◽  
M. Rybanský
Keyword(s):  
Solar Corona ◽  
Time Resolution ◽  
Active Regions ◽  
High Time ◽  
High Time Resolution ◽  
List Type ◽  
Type Number ◽  
Coronal Line ◽  
Global Cycle

AbstractThis paper deals with a possibility to use the ground-based method of observation in order to solve basic problems connected with the solar corona research. Namely:1.heating of the solar corona2.course of the global cycle in the corona3.rotation of the solar corona and development of active regions.There is stressed a possibility of high-time resolution of the coronal line photometer at Lomnický Peak coronal station, and use of the latter to obtain crucial observations.

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