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Study of atomic and molecular many- body processes in astrophysics (Record no. 14715)

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
Holdings
Withdrawn status Lost status Source of classification or shelving scheme Damaged status Not for loan Home library Current library Shelving location Date acquired Full call number Barcode Date last seen Price effective from Koha item type
    Universal Decimal Classification     IIA Library-Bangalore IIA Library-Bangalore General Stacks 20/07/2002 043:52/ MAJ 15637 05/11/2021 20/07/2002 Thesis & Dissertations

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