PhD Dissertations by MUM Students – Physics

The full-text pdf copies of all University PhD dissertations published since mid-1996 are now available free online to on-campus users.

All users can order any of the University dissertations for a fee by using the “Order” link on the citations below or on the abstract pages to which they link. Additional pre-1996 dissertations will be available for free to on-campus users in the future.

Dissertations [Updates: In Progress]

Kelley, Stephen — Physics

Aspects of the flipped unification of strong, weak and electromagnetic interactions.

Order No.9133555

We explore phenomenological aspects of a recently- proposed Flipped SU(5) x U(1) supersymmetric GUT which incorporates an economical and natural mechanism for splitting Higgs doublets and triplets, and can be derived from string theory. Using experimental values of sin squared theta sub{W} and the strong QCD coupling, we estimate the grand unification scale M sub{G}, where the strong and weak coupling strengths are equal, and the superunification scale M sub{SU}, where all couplings are equal. We find typical values of M sub{G} [in the range] 10 superscript{15} to 10 superscript{17} GeV, with M sub{SU} somewhat higher and close to the value suggested by string models. We discuss different mechanisms for baryon decay, finding that the dominant one is gauge boson exchange giving rise to p to e sup{+} pi sup{0}, bar nu pi sup{+} and n to e sup{+} pi sup{-}, bar nu pi sup{0} with partial lifetimes ~10 sup{35 ± 2} y. We show that a large GUT symmetry-breaking scale M sub{G} is naturally generated by radiative corrections to the effective potential if a small amount ~m sub{W} of soft supersymmetry breaking is generated dynamically at a large scale. We conclude that such spontaneous symmetry breaking causes sizable D-term contributions O(m sub{W}) to all low energy scalar masses which may provide a means to discriminate among various candidate gauge groups. We analyze the low-energy effective theory obtained using the renormalization group equations, demonstrating that electroweak symmetry breaking is obtained if m sub{t} ~60 to 90 GeV. We analyze the spectrum of sparticles, with particular attention to neutralinos. Analysis of the dark matter properties of the theory shows that the LSP decays before cosmological nucleosynthesis, repopulating the fermionic “flatino” partner of the flaton, giving a viable candidate for metastable dark matter. Finally, we show that the definition of the unified field provided by Maharishi’s Vedic ScienceSM supports the identification of the unified field with pure consciousness, and we present structural parallels between the sequence of theories produced through spontaneous dynamical symmetry breaking and the sequential emergence of natural law described by the Ved. Source: DAI, 52, no. 06B, (1991): 3119

This dissertation tested the hypothesis that enlivening the holistic source of pure intelligence/Tao by Maharishi’s Transcendental MeditationŒ (TM) program develops holistic intelligence, optimizing all aspects of mental functioning and personality. Holistic intelligence was operationalized by six culture-fair tests: Test of Creative Thinking (TCT-DP); Contructive Thinking Inventory (CTI); Spielburger’s State-Trait Anxiety Inventory (STAI); Inspection Time (IT); Cattell’s Culture Fair Intelligence Test (CFIT); Group Embedded Figures Test (GEFT), which respectively measure creativity; practical intelligence; anxiety (experiential intelligence); neural efficiency (physiological intelligence); fluid intelligence; and field independence (contextual intelligence).

Three randomized, blind, controlled studies (6-12 months) were conducted with 363 Chinese students, mean age 14.5-17.5. The first study compared TM with Napping, and no-interest subjects. The second study compared TM with Contemplation technique, and control. The third study compared TM with control.

The emergence of 5 to 6 distinct components from factor analyses supported that multiple intelligences exist. MANCOVA showed that the TM groups increased multiple intelligences significantly more than controls in three studies. For the three studies combined, the TM groups improved more than controls on all tests: TCT-DP (p < .000000008); CTI (p < .00009); STAI (p <.00001); IT (p < .0003); CFIT (p <.001); GEFT (p <.00000004). The effect sizes were largest on measures associated with deeper levels of mind, creativity (.77), anxiety (.63), field independence (.58), practical intelligence (.5), inspection time (.46), fluid intelligence (.4); MANCOVA showed that TM increased holistic intelligence more than Contemplation (p <.000001) or Napping (p <.000045).

These findings confirmed that intelligence is holistic and can be developed through regular experience of pure intelligence/Tao through Maharishi’s Transcendental Meditation program. They confirm that TM has the ability to simultaneously improve a broad range of mental abilities which has a far-reaching impact on the field of intelligence and education. Source: DAI, 56, no. 06A, (1995): 2178

 

Kleinschnitz, Kurt Warren — Physics

Solution propagation in stimulated Raman scattering for inhomogeneously broadened media.

Order No.9534646

This dissertation describes the propagation and generation of solitons in stimulated Raman scattering (SRS) at low intensities for homogeneously and inhomogeneously broadened media. It includes a theoretical and numerical analysis of the propagation of SRS solitons, and a numerical analysis of their generation. The effects of broadening and of frequency detuning of the pump and the Stokes beams off exact Raman resonance are included in the equations describing SRS. The main result is that even though SRS solitons decay in homogeneously broadened media for a non-zero value of the detuning, they are stable in inhomogeneously broadened media to lowest order in the linewidth. The analytical method that is used employs physical conservation laws for energy and the total phase shift of the soliton. In the perturbation theory, the solutions of the damped equations are assumed to be of one-soliton form as functions of time, with position dependent parameters such as width, amplitude and temporal position. Good agreement is found between the analytic results from the perturbation theory and direct numerical integration of the equations of motion describing SRS. Source: DAI, 56, no. 06B, (1995): 3263

 

Luimes, Arthur — Physics

Solution propagation in stimulated Raman scattering for inhomogeneously broadened media.

Order No.9534646

This dissertation describes the propagation and generation of solitons in stimulated Raman scattering (SRS) at low intensities for homogeneously and inhomogeneously broadened media. It includes a theoretical and numerical analysis of the propagation of SRS solitons, and a numerical analysis of their generation. The effects of broadening and of frequency detuning of the pump and the Stokes beams off exact Raman resonance are included in the equations describing SRS. The main result is that even though SRS solitons decay in homogeneously broadened media for a non-zero value of the detuning, they are stable in inhomogeneously broadened media to lowest order in the linewidth. The analytical method that is used employs physical conservation laws for energy and the total phase shift of the soliton. In the perturbation theory, the solutions of the damped equations are assumed to be of one-soliton form as functions of time, with position dependent parameters such as width, amplitude and temporal position. Good agreement is found between the analytic results from the perturbation theory and direct numerical integration of the equations of motion describing SRS. Source: DAI, 56, no. 06B, (1995): 3263

 

Parker, Ronald J. D. — Physics

The effects of cold dark matter on big bang nucleosynthesis.

Order No. 8918486

We show that the annihilation of cold, weakly-interacting dark matter candidates (chi) subsequent to chi chi freeze-out can significantly affect the primordial abundance of light elements. The largest effects are (1) between the n/p freeze-out temperature (T = 0.7 MeV) and the onset of nucleosynthesis at T = 0.1 MeV, chi chi annihilations increase the n/p ratio, leading to increased 4He production; (2) following 4He synthesis, baryonic products n, n(bar), p of chi chi annihilations dissociate some the the 4He into D and 3He, leading to increased D + 3He abundances; (3) toward the end of nucleosynthesis, neutrons from chi chi annihilation lead to n + 7Be to become p + 7Li, resulting in increased 7Li + 7Be production for low values of eta = n (sub)b / n (sub)gamma and decreased 7Li + 7Be production for large eta, and (4) long after nucleosynthesis, once the universe cools below T = 1 keV, the electromagnetic shower produced by electrons, positrons and photons from residual chi chi annihilations cause further dissociation of 4He, leading to increased D + 3He abundances. The most important result is that for Direc and Majorna neutrinos, the 7Li constraints on eta from SBBN are noticeably affected, with larger values of eta being favored.

A summary of scattering rates for processes in the electromagnetic shower, containing corrections to numerous misprints in other sources, is presented in an Appendix. A listing of FORTRAN code used in the shower calculation is also included. Finally, the results are discussed in the light of Maharishi’s Vedic Science, an ancient science which presents both knowledge and experience of the transcendental basis of life. Source: DAI, 50, no. 05B, (1989): 1987

 

Rawal, Sunil Christopher — Physics

Dynamical supersymmetry breaking at the weak scale and the determination of the dilaton amd moduli vevs.

Order No.9713471

This dissertation demonstrates a mechanism whereby generic string-inspired supergravity models naturally and dynamically break supersymmetry and determine the vevs of the dilaton, moduli and Higgs fields. The key to the mechanism is to make an explicit construction of string-inspired supersymmetric models renormalized at M sub z where the parameters are considered as a function of undetermined field vevs. The field dependence of the gravitino mass and gauge coupling at low energies provides sufficient structure to determine the vevs of all scalar fields. We determine necessary conditions for stable minima (and hence a dynamically determined gravitino mass) in supersymmetric SU(N) models. In the context of the SSM, renormalization effects of the top-quark Yukawa eventually trigger instability of the potential at the origin. Thus, supersymmetry breaking naturally turns on at the weak-scale. The excellent phenomenology of the SSM is then inherited by our mechanism. We show that a mu-term of non-renormalizable origin naturally stabilizes the theory. With these demonstrations in hand, we go on to explain how the mechanism avoids non-renormalization theorems of supersymmetric field theories and string theories. Source: DAI, 57, no. 11B, (1997): 7014

 

Saatcioglu, Fahri — Physics

Multiple DNA-protein interactions at the aryl hydrocarbon (Ah)- responsive enhancer of the CYP1A1 gene.

Order No. 9025204

The polycyclic aromatic hydrocarbon-inducible cytochrome P450IA1 (CYP1A1) gene is capable of both detoxifying polycyclic aromatic compounds, such as tetrachlorodibenzo-p- dioxin (TCDD), 3-methylcholanthrene and beta-napthoflavone, and converting some compounds to highly active carcinogens and mutagens. Both transcriptional and post-transcriptional mechanisms have been shown to be important in the regulation of the CYP1A1 gene. Previously, two xenobiotic response elements, XRE1 and XRE2, both of which can activate transcription of the CYP1A1 gene, were identified. We present evidence in the following chapters that three distinct factors, XF-A1, XF-A2, and XF-B, which has been identified as the Ah receptor, interact specifically with the XRE sequence motif at the PAH-responsive enhancer of the CYP1A1 gene. XF-A1 and XF-A2, which bind to the XRE motif, have not been described previously. Our footprinting analysis shows that, although XF-A1 and XF-A2, and the Ah receptor all bind to the same 15 base pair sequence domain, they interact with distinctly different nucleotides. Our analysis indicates that XF-A1 and XF-A2, and the Ah receptor are the products of different genes, that their expression is regulated differently, and that these two factors require different cofactors. Comparison of the binding activities of the Ah receptor, XF-A1 and XF-A2 for XRE1 and XRE2 reveal substantial differences in affinity. In addition, there are differences in the interaction of the Ah receptor with XRE1 and XRE2.

In particular, the following points can be made regarding these three factors: (1) XF-A1, XF-A2, and the Ah receptor are probably different gene products, since mutant cell lines defective in the Ah receptor have normal levels of XF-A1 and XF-A2 activity. (2) XF-A1 and XF-A2 activities are constitutively expressed in the nucleas whereas Ah receptor- related DNA-binding activity appears in the nucleus only after treatment with polycyclic compounds. (3) Zn2+ is an essential cofactor for the Ah receptor, but not for XF-A1 or XF-A2, consistent with the earlier hypothesis that the Ah receptor is a member of the steroid and thyroid hormone receptor super- family. (4) The affinities of the Ah receptor, XF-A1 and XF-A2 for XRE2 are 15- and 50- fold weaker, respectively, than for XRE1, which suggests that the two XREs may differ in their contribution to CYP1A1 gene transcription. (5) In contrast to previous studies in Hepa1 cells, a single copy of either XRE has no discernible transcriptional activity in primary cultures of rat hepatocytes, but a 115-bp region containing both XREs has enhancer activity in response to both TCDD and cycloheximide. [Abstract shortened.] Source: DAI, 51, no. 08B, (1990): 3696

 

Tanaka, Toshiaki — Physics

Supersymmetric flavor changing neutral currents: exact amplitudes and phenomenological analysis (squark mass matrices)

Order No. 9323143

I present an exact calculation of the most general supersymmetric amplitudes for $Ksp0-bar{K}sp0$ and $Bsp0- bar{B}sp0$ mixing resulting from gluino box diagrams. I use these amplitudes to place general constraints on the magnitude of off-generational, flavor-changing mass mixings in the squark mass matrices (with arbitrary chirality structures) that can arise both in and beyond the minimal supersymmetric Standard Model (MSSM). I use the renormalization group equations to estimate these mass mixings in the MSSM and in non-minimal supersymmetric models in terms of a general parameterization of universal soft supersymmetry breaking.

I show that while these mass mixings are too small in the MSSM to yield any observable effects, the converse is true in most nontrivial extensions of the MSSM, including supersymmetric GUTs.

In non-minimal supersymmetry, the $Ksb{L}-Ksb{S}$ mass difference in sensitive to such contributions from supersymmetric particles with masses up to 100 TeV (10 TeV for the $Bsb{L}-Bsb{S}$ mass difference), and the CP impurity parameter $epsilonsb{K}$ is sensitive to sparticle masses up to 1000 TeV. I show that supersymmetric CP violation can be predominantly “superweak” (i.e., contribute mainly to $epsilonsb{K}$) or “milliweak” ($epsilonspprime$) depending on the chirality of the off-generational squark mass mixings. The rare decay $bto sgamma$ is less sensitive than the aforementioned constraints, but probes somewhat different squark mass mixings. The lepton number violating decay $muto egamma$ is very sensitive to off-generational slepton mixing for sleptons up to a TeV. All these processes provide valuable information regarding the structure of physics beyond the MSSM pertaining to arbitrarily high mass scales, including the nature of supersymmetry breaking. Source: DAI, 54, no. 04B, (1993): 2024

 

Weller, Richard K — Physics

Dynamical analysis of human EEG: A comparative study of different states of wakefulness

Order Number: 304091312

This thesis documents an application of dynamical time series analysis to human EEG recorded in different states of wakefulness. In this study, the assumed brain dynamics were reconstructed using a multi-lead algorithm applied to data from six simultaneously recorded channels. A version of the Grassberger-Procaccia algorithm was used to compute estimates of the correlation dimension of the resulting attractors.

The EEG signals were taken from four subjects during a variety of mental states including eyes-open rest, eyes-closed rest, simple problem-solving, and the Transcendental Meditation (TM) technique of Maharishi Mahesh Yogi. Previous studies using spectral analysis suggest that distinct patterns of high spatial coherence in the EEG are characteristic of the TM technique. Since brain dynamics are almost certainly nonlinear, this study investigated dynamical methods as a complement to spectral analysis in EEG research.

 

Windenberger, Claude — Physics

Decoherence, two-mode squeezing and quantum noise reduction in a cavity Raman laser

Order No. 9633804

In this dissertation, we study squeezing for the Stokes and Anti-Stokes fields generated in a model of a single-mode Raman laser in a loss-less cavity with classical pump and unsaturated medium, for arbitrary homogeneous broadening and dispersion. Generalizing the notion of two-mode squeezing to allow for arbitrary linear combinations of the two modes in the definition of the quadrature variables, we find that the two output modes, for this general notion, always exhibit quadrature squeezing with noise reduction below the vacuum level. We also discuss our results and the general area of quantum optics in terms of the structures of intelligence as presented in Maharishi’s Vedic Science. Finally, we report on a practical aspect of our dissertation research, the “European Alliance with Natural Law Project”, whose purpose was to introduce Maharishi’s programs, as presented in “Maharishi’s Master Plan to Create Heaven on Earth”, to our hometown Strasbourg, France, and in particular to the European Parliament located there. Source: DAI, 57, no. 06B (1996): p. 3823

 

Wolfson, Richard M. — Physics

Generation and propagation of Raman solitons at high intensity

Order No. 8921896

This research is a theoretical study of the generation and propagation of solitons in stimulated Raman scattering at high intensity. This study extends previous research by incorporating, in particular, effects of the Stark shift and medium saturation, in addition to the detuning of the fields off medium resonance and the broadening of the Raman linewidth due to collisions in the medium (collisional coherence decay). The main result is that by balancing the above effects, the maximum pump intensity can increase over propagation even with damping from collisional coherence decay.

The research employs both numerical and analytic techniques. The analytic method from soliton perturbation theory assumes soliton solutions of the damped equations to be of the one-soliton form as functions of time. Good agreement is found between the analytic results and direct numerical integration. Source: DAI, 50, no. 06B, (1989): 2475

 

Ziegler, Veronique — Physics

Testing grand unified theories using gauge coupling unification and proton decay

Order No. 9633805

We test the validity of Grand Unified Theories by the simultaneous constraints from proton decay and gauge coupling unification. For minimal supersymmetric SU(5), we obtain a strict bound $alphasb3 > 0.117,$ which is above measurements of $alphasb3$ from deep inelastic scattering and the charmonium spectrum by more than 3$sigma.$ This signals the failure of the minimal SU(5) model. The dismissal of ordinary SU(5) gives a strong incentive to investigate flipped supersymmetric SU(5) $times$ U(1). A careful analysis, including all threshold effects, indicates that the parameter space of flipped supersymmetric SU(5) $times$ U(1) is compatible with experimental range. We obtain an upper bound on the splitting between the heavy mass-scales $Msb{Dsp{c}}$ and $Msb{X}$, of the order of 10$sp4$. We find gravitational perturbations affecting predictions from the level of the Planck scale to be negligible. An attempt to increase the superunification scale, $Msb{SU}$, via the mass of the right handed neutrino, gives us a value for $Msb{SU}$ still short of the string scale. Source: DAI, 57, no. 06B (1996): p.3814