MARC details
000 -LEADER |
fixed length control field |
03732nam a2200253Ia 4500 |
003 - CONTROL NUMBER IDENTIFIER |
control field |
IN-BaIIA |
005 - DATE AND TIME OF LATEST TRANSACTION |
control field |
20211111120622.0 |
008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION |
fixed length control field |
211028s9999 xx 000 0 eng d |
040 ## - CATALOGING SOURCE |
Transcribing agency |
IIA Library |
080 ## - UNIVERSAL DECIMAL CLASSIFICATION NUMBER |
Universal Decimal Classification number |
043:52 |
Item number |
MAJ |
100 ## - MAIN ENTRY--PERSONAL NAME |
Personal name |
Majumder,Sonjoy |
9 (RLIN) |
26317 |
Relator term |
Author |
245 #0 - TITLE STATEMENT |
Title |
Study of atomic and molecular many- body processes in astrophysics |
Remainder of title |
a thesis submitted for the degree of Doctor of Philosophy in Bangalore University, Bangalore |
Statement of responsibility, etc. |
Sonjoy Majumder |
Medium |
[Ph.D Thesis] |
260 ## - PUBLICATION, DISTRIBUTION, ETC. |
Place of publication, distribution, etc. |
Bangalore |
Name of publisher, distributor, etc. |
Indian Institute of Astrophysics |
Date of publication, distribution, etc. |
2001 |
300 ## - PHYSICAL DESCRIPTION |
Extent |
xvi, 134p. |
500 ## - GENERAL NOTE |
General note |
Thesis Supervisor B. P. Das |
502 ## - DISSERTATION NOTE |
Degree type |
Doctor of Philosophy |
Name of granting institution |
Bangalore University , Bangalore |
Year degree granted |
2001 |
520 ## - SUMMARY, ETC. |
Summary, etc. |
Atomic and molecular processes in astronomical objects have profound implications. Many of those objects in which certain atomic and molecular species have been detected are the sites for evolution of stellar envelopes and star formations. Measurements of atomic and molecular line intensities are powerful diagnostic tools for the exploration of many astrophysical processes. Accurate calculations of energy levels,<br/>lifetimes of states, oscillator strengths and shapes of the atomic and molecular transition lines are often necessary to understand those processes. Rigorous treatments of atomic and molecular many-body effects are necessary for accurate calculations of these quantities. Such calculations have become important with the advent of high resolution spectrographs used in several ongoing missions for solar and stellar projects. Even improved experimental data are not adequate for them. Forbidden lines, which is one of the important features in this thesis work, are difficult to measure. Here we have employed various many-body approaches to calculate electronic properties of some atoms, ions and molecules which have astrophysical importance. Both non-relativistic and relativistic studies have been performed using perturbative and non-perturbative approaches. Effective valence shell Hamiltonian (HV) theory, one of the most advanced nonrelativistic approaches to multireference many-body perturbation theory (MBPT) is used to calculate binding energies (energy relative to first ionization threshold), excitation energies, oscillator strengths and transition probabilities of neutral carbon and calcium. The same method is used for calculating ground state energy difference between the cyclic and linear isomers of propynlidyne (C3H), as well as their harmonic vibrational frequencies, ionization potentials, electron affinities, excited state energies, dipole moments and oscillator strengths, some of which have not been reported before. One of the most important forbidden transitions, magnetic quadrupole transitions for Be-like ions are calculated using the multiconfiguration Dirac-Fock met.hod, which is a self consistent variational relativistic many-body method. The leading relativistic correction to the Coulomb interaction known as the Breit interaction is included in these calculations using first-order perturbation theory. The \v('ak allowed transitions of Mg II are accurately computed using one of the most powerful non-perturbative size-extensive approaches, the coupled cluster (CC) method. A new approach to generate the Dirac-Fock (DF) orbitals using finite basis set expansions is developed. These DF orbitals are used in the CC calculations to achieve high accuracies for various electronic properties of atoms.<br/> |
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM |
Topical term or geographic name entry element |
Astrophysics |
9 (RLIN) |
794 |
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM |
Topical term or geographic name entry element |
Atomic Properties |
9 (RLIN) |
26318 |
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM |
Topical term or geographic name entry element |
Atomic Systems |
9 (RLIN) |
19508 |
700 ## - ADDED ENTRY--PERSONAL NAME |
Personal name |
B. P. Das |
Relator term |
Supervisor |
9 (RLIN) |
48865 |
856 ## - ELECTRONIC LOCATION AND ACCESS |
Uniform Resource Identifier |
<a href="http://prints.iiap.res.in/handle/2248/118">http://prints.iiap.res.in/handle/2248/118</a> |
Link text |
Click Here to Access eThesis |
942 ## - ADDED ENTRY ELEMENTS (KOHA) |
Koha item type |
Thesis & Dissertations |
Source of classification or shelving scheme |
Universal Decimal Classification |