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projectideas [2014/05/14 14:07]
cyburt created
projectideas [2014/06/06 13:39] (current)
cyburt
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-====== Project Ideas ======+====== ​PROJECTS ====== 
 +Projects: ​ **[[Projects]]**,​ **[[ProjectIdeas|Project Ideas]]** 
 +---- 
 +==== Project Ideas ==== 
 + 
 +== Neutrino Driven Wind == 
 + 
 +    - By doing a literature search, determine three different types of neutrino spectra that are appropriate for neutrino driven wind conditions. Alter the reaction network to include neutrino interactions on free nucleons. ​ Calculate an abundance pattern for a neutrino driven wind model with the three different types of spectra. ​ Analyze the results and discuss what characteristics of the spectra lead to different outcomes. ​  
 + 
 +== Neutron Star Merger r-process == 
 + 
 +    - Determine, using the literature, representative conditions for tidal ejection of material from neutron star mergers and for neutrino driven winds. ​ Calculate, using the reaction network, abundance patterns for each and compare the results. ​ Discuss why the patterns look different. 
 + 
 +== BBN: == 
 + 
 +   * Quantify the sensitivities of the light elements to variations in the key reaction rates. ​ Propagate uncertainties in nuclear reation rates via Monte Carlo to evaluate the uncertainties in the BBN predictions. 
 + 
 +   * Explore the consequences of new physics during BBN.  This can include: ​ adding neutrino species, modification of the gravitational constant, neutrino degeneracy and neutrino oscillations. ​  
 +     * For a more challenging calculation,​ consider the effect of dark matter decays that dissociate 4He.   
 +     * For each of these, what is the effect on the light elements? ​  
 +     * How can we use light element and cosmological (e.g., CMB) observations to constrain these scenarios?​ 
 + 
 + 
 +== Exploding a polytropic star == 
 + 
 +    - Create a hydrostatic configuration for a polytropic star.  Solutions can be derived from the Lane-Emden equation ([[http://​en.wikipedia.org/​wiki/​Lane%E2%80%93Emden_equation|Lane-Emden equation]]). ​  
 +      - Please look in the "​Explode a Polytropic Star" folder in the Projects/​Project Ideas folder in the Document Server for a python code that calculates the profile of a polytropic star. 
 +    - For an initial condition, increase the central pressure (and only the central point) by some factor of the hydrostatic value (just as in the Sedov Blast Wave). 
 +    - Evolve the star given this deposition of energy in the center of the star. 
 +    - Questions you can try to answer 
 +     * Find the factor needed to explode the star.  Is this derivable analytically?​ 
 +     * How do trajectories differ when the factor is: half, equal, and twice the critical explosion value? 
 +     * Do all trajectories escape? 
 +     * How do things change with different polytropic indices? 
 +     * Assume an initial composition for all fluid elements. 
 +     * How does the composition in each trajectory evolve? 
 +     * What does the final composition of the whole “star” look like? 
 +     * How does the final composition of the escaped trajectories compare to the total? 
 + 
 +== Post-Processing nucleosynthesis ==   
 + 
 +   * Extract a Lagrangian profile from the blast wave simulation and use the network to calculate the nucleosynthesis. 
 + 
 +== Numerics of Blast Waves== ​  
 + 
 +   * Explore how resolution, dimensionality and the nature of the grid affect a blast wave simulation. 
 + 
 +== Reaction Sensitivity studies ==   
 + 
 +   * Change reactions in the network and examine the impact on the abundances. We can easily do this for CCSN, TNSN, novae, XRB, maybe others.  
 + 
 +== Impact of Neutronization on supernova nucleosynthesis == 
 + 
 +   * Vary the initial electron fraction and examine how CCSN nucleosynthesis changes. 
 + 
 +== hydro:== 
 + 
 +   * Simulate the effects of a near-earth supernova explosion at 10 pc (the "kill radius"​) and the resulting collision of the blast with solar wind. Will the supernova reach 1 AU?  How does the answer depend on the supernova explosion energy? ​ Distance? ​ Interstellar density? 
 + 
 + 
 +== nuke network: ​== 
 + 
 +   * Simulate the s-process under AGB conditions. ​ Compare to solar system abundances and presolar grains. ​ How does the result depend on initial composition? ​ How good is the waiting point approximation?​
  
  
  
projectideas.1400090875.txt.gz · Last modified: 2014/05/14 14:07 by cyburt