Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 42 for “"Nucleosynthesis"”.
-
Precision frontiers of big bang nucleosynthesis
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2024-08-01
-
The Influence of Matter-Antimatter Domains on Big Bang Nucleosynthesis
In der vorliegenden Arbeit habe ich mich mit den Auswirkungen eventuell im fruehen Universum vorhandener Antimaterieregionen auf die Haeufigkeiten der leichten Elemente beschaeftigt. Praktisch das gesamte Deuterium und der ueberwiegende Teil der Helium-4 Kerne, die wir heute im Universum …
-
Following Carbon's Evolutionary Path: From Nucleosynthesis to the Solar System
Studies of carbon's evolutionary path have been conducted via millimeter and submillimeter observations of circumstellar envelopes (CSEs), planetary nebulae (PNe), molecular clouds and comets. The 12C/13C isotope ratio was measured in Galactic molecular clouds using the CN isotopologs. A gradient …
-
Mixing and Nucleosynthesis in Low- and Intermediate-Mass AGB Stars
The existence of carbon stars brighter than M$\sb {\rm bol}$ = $-4$ can be understood in terms of dredge up in thermally pulsing asymptotic giant branch (AGB) stars. Models in this study include the effect that carbon recombination has upon opacity, and it is shown that a low-metallicity (Z = …
-
Dynamics of primordial phase transitions, primordial magnetic fields, and Big Bang nucleosynthesis
… primordial magnetic fields, and Big Bang Nucleosynthesis. In particular, (1) I have derived the effects of magnetic fields on nucleon and particle reaction rates of astrophysical significance. The sensitivity to the presence of arbitrary degeneracy and polarization has also been examined. …
-
Probing and Raising the Lithium Problems With Hadronic Gamma Rays and Cosmic -Ray Nucleosynthesis
… a new, model-independent way of testing the CR nucleosynthesis of Li. We apply this tool to test a, still hypothetical, cosmological CR population. Moreover, our approach reveals yet another Li problem. The isotope 6Li is made only in CR interactions where the standard assumption is that the …
-
Use of Active Target Detectors in Nuclear Astrophysics: Nucleosynthesis of Fluorine and Fusion of Neon
… reaction 15N(a,g)19F, a reaction involved in the nucleosynthesis of fluorine, was determined using the principle of detailed balance and a photodisintegration of fluorine experiment with a single fluid bubble chamber. The system of neon isotope fusions 20,22,24Ne + 20,22Ne, relevant to physics …
-
Primordial Nucleosynthesis in the New Age of Cosmology: Determining Uncertainties, Examining Concordance, and Probing New Physics
Big bang nucleosynthesis (BBN) has long played a key role in the standard cosmology. BBN accurately predicts the primordial light element abundances of deuterium, helium and lithium. The general concordance between the predicted and observed light element abundances provides a direct probe of the …
-
Primordial Nucleosynthesis In The New Age Of Cosmology: Determining Uncertainties, Examining Concordance, And Probing New Physics
Big bang nucleosynthesis (BBN) has long played a key role in the standard cosmology. BBN accurately predicts the primordial light element abundances of deuterium, helium and lithium. The general concordance between the predicted and observed light element abundances provides a direct probe of the …
-
Using fusion-product spectroscopy to study inertial fusion implosions, stopping power, and astrophysical nucleosynthesis at OMEGA and the NIF
By measuring energetic charged-particle products from fusion reactions occurring in plasmas, nuclear diagnostics can be used to study the properties of the burning plasma, as a probe of the plasma, or of the fundamental fusion reaction physics. In this thesis, fusion product spectroscopy is used to …
-
Indirect 2H(d,p)3H and 2H(d,n)3He fusion reactions measurement at energies relevant for Big Bang Nucleosynthesis
… 2H(d,p)3H and 2H(d,n)3He in the Big Bang Nucleosynthesis (BBN) astrophysical scenario. In the beginning is presented this phase of the early universe and why the BBN model is still fine tuned with new results coming from observations and laboratory measurements. This model (if BBN is …
-
Testing stellar models with observations from AGB and post-AGB stars
… ejected mass contains many products of internal nucleosynthesis. However, theoretical studies of the evolution of red-giants are inhibited by uncertainties in important processes such as mass loss, convective mixing, and grain formation in stellar winds. From an observational point of view it is …
-
Testing stellar models with observations from AGB and post-AGB stars
… ejected mass contains many products of internal nucleosynthesis. However, theoretical studies of the evolution of red-giants are inhibited by uncertainties in important processes such as mass loss, convective mixing, and grain formation in stellar winds. From an observational point of view it is …
-
Beryllium-9 in Cluster Effective Field Theory
… of nuclei are important in the study of stellar nucleosynthesis, I introduce the Hyperspherical Harmonics basis with which the calculations were carried out. The following chapter has the momentum space as the main subject, ending with some results from the program. EFT and cluster nuclei are …
-
Chemical abundances in planetary nebulae in NGG 6822
… enrichment indicates it is a product of Primary Nucleosynthesis, and Type I planetaries are probably significant in N enrichment of the ISM. Type II planetaries exhibit a He and N enrichment of a lesser magnitude than Type I; factors of 1.4 and 5, respectively. This lower enrichment indicates N …
-
Applications of particle physics to the early universe
… of Baryogenesis, of Dark Matter, and of Big Bang Nucleosynthesis. The analysis of the data of the experiment WMAP on the CMB for the search of a non-Gaussian signal is also presented and it results in an upper limit on the amount on non-Gaussianities which is at present the most precise and …
-
Study of the $^{19}$F(p,$\alpha$)$^{16}$O reaction through the Trojan Horse Method and its astrophysical enviroment
Fluorine nucleosynthesis takes place in the hydrogen-helium intershell region of Asymptotic Giant Branch (AGB) stars and in the same region also the $s$ elements are produced. Because fluorine is produced in the He-intershell and then dredged up to the surface together with $s$ process elements, …
-
BETA DECAY STUDIES AS A TOOL TO INVESTIGATE NUCLEAR STRUCTURE IN THE N-RICH PO-FR REGION AND IN P-RICH CD ISOTOPES
… inputs for the description of the r-process nucleosynthesis. The second part of the thesis is focused on the study of the β-delayed decay pattern in 100,101,102Cd. New levels were added to the level scheme of 101Cd, and compared to large-scale shell model calculations. In 100,102Cd, the …
-
Some numerical investigations in cosmology
… doubts on the classical treatment at Big Bang Nucleosynthesis. We propose the DBI chameleon, a consistent high energy modification of the chameleon theory that dynamically renders it weakly coupled to matter during the early universe thereby avoiding the breakdown of calculability. We …
-
Inflationary Models: Observables and Viability
… the transition from in ation to big bang nucleosynthesis, known as reheating. This phase is important as it can a ect the details of the in ationary power spectrum and the present dark matter abundance. In simple models, the universe is dominated by a nearly-homogeneous in aton condensate …
Page 1 of 3