Jacob Moldenhaur Ph.D.

Physics Department
Haggerty Science Center #40

Department Chair and Associate Professor

972-721-4117
jmoldenhauer@eliogonzalez.com

Dr. Jacob Moldenhauer received his Ph.D. in physics from the University of Texas, Dallas in August 2010.     His primary research interest is in computational and theoretical cosmology; looking for answers to the mysteries of the Universe.  He is always looking for new and innovative teaching methods for physics and related fields. 

Ph.D. In Physics August 2010        The University of Texas at Dallas  
Dissertation Defense:  Dynamics and Phenomenology of Higher Order Gravity Cosmological Models  June 11, 2010 
M.S. In Physics May 2007       The University of Texas at Dallas  
B.A. In Physics May 2001       The University of the Ozarks  
Thesis:  Verification of the Expansion of the Universe

我的研究是理论宇宙学，使用分析和数值计算， 其中包括使用来自NASA和其他国际数据库的可用数据.  我使用的计算资源如高性能计算集群，复杂 数值算法和交互式模拟都与最近的观测相结合 数据集，以寻求一些最引人注目和仍然挥之不去的问题的答案 about the universe.  How old is the universe?  When and how did it begin?  Was there something before the Big Bang?  What is the cause of the current accelerated expansion of the universe (also called the cosmic acceleration)?  What size and shape is the universe?  What is the ultimate fate of the universe?  Most of my current work involves determining the cause of the cosmic acceleration. As the universe expands, other galaxies accelerate away from us. Physicists do not yet know the cause of this accelerated expansion.  It could be due to some form of as of yet unknown dark energy, i.e. Cosmological Constant, requiring a negative pressure and negative equation of state.  Another popular explanation for the cosmic acceleration 来自于广义相对论的延伸，在宇宙学上起作用 scales of distances, e.g. modified gravity.  An important part of this project involves 能够通过观察区分这些不同的理论并执行 tests to falsify them.  I explored and falsified many modified gravity models in my dissertation, Dynamics and Phenomenology of Higher Order Gravity Cosmological Models, and we developed parameterizations to falsify general relativity at cosmological scales with the Integrated Software in Testing General Relativity (ISiTGR)，这将被证明是非常有用的，因为接下来会有更精确的数据可用 few years. 

Specifically, I test cosmological models against experimental data sets.  Constraints 模型中的参数值将支持或排除背后的理论 the model.  It is my desire, not only to answer some of these questions, but also be able to allow non-cosmologists to understand the explanations and cosmological methodologies.  So, I also focus some of my time on cosmology education research.  I began constructing cosmological modeling simulations with the help of Easy Java 我和弗朗西斯马里昂大学的同事们合作完成了EJS (FMU) and most recently at the University of Dallas (UD).  These simulations are packaged as CosmoEJS, an interactive cosmology simulation that allows users to fit cosmological models to actual data sets using EJS. These simulations combine real-time plotting and numerical 拟合说明如何将理论模型与实验数据进行比较 sets to test a cosmological model.  The simulations contain genuine data sets from recent cosmological surveys with options for testing more than one model at a time for easy visual and numerical comparisons.  The visual comparisons allow users to directly see why some models match the data and others do not, while the numerical comparisons are for refining the parameter values for a best-fit model.  Several colleagues 在美国物理学会(TSAPS)德州分会2014年秋季会议上 remarked that these programs were exactly what they were looking for in the field of cosmology.  More information on these simulations  can be found in our articles, 现代宇宙学:使用最新观测数据的交互式计算机模拟 Sets, (Am. Jour. Phys., Vol. 81, Issue 6, 2013) and Exploring the constraints on cosmological models using CosmoEJS, (JCAP11(2018)011).  (Both projects were completed with undergraduate students.)

At the 2019 Texas Symposium on Relativistic Astrophysics in Portsmouth, England, I presented a 30 minute talk on this work on CosmoEJS. This work was recently highlighted with the 2019 Nobel Prize in Physics. In the 美国物理学杂志(AJP)宣布了诺贝尔物理学奖， our original CosmoEJSarticle in AJP is given as one of three Top Articles in Cosmology, along with those of the Nobel Laureate for content related to the 2019 Nobel Prize in Physics.

This is an exceptional arena from which undergraduates new to cosmology can begin 他们的研究，因为除了学习的主题，他们也帮助 to develop tools for their peers.  I had undergraduate students during my two years 并在过去的几年里继续与特拉华大学的本科生合作 为这些项目增加了新的宇宙观测模拟，如 well as new functionalities for these programs.  Once they become familiar with the 材料方面，他们更有准备去理解理论研究，这涉及到 不仅要知道观测结果，还要知道理论模型是如何构建的.  We also make use of the simulations in the classroom and education outreach, like astronomy club.  I have my students present their program to a non-majors class for the opportunity to try out their tools on audiences less familiar with the work.  这给了他们一个机会，不仅展示他们的理解，而且提高 their ability to communicate about the field with their peers. 

渴望探索宇宙问题的本科生学习高 Performance Computing (HPC) skills to test cosmological models with observational data sets.  These tests are performed using a modified version of the publicly available Monte Carlo Markov Chain code for cosmology,cosmoMC, (A. Lewis and S. Bridle, Phys. Rev. D66, 2002).  This code is used along with certain packages, or modules like ISiTGR, (J. Dossett, M. Ishak and JM, Phys. Rev. D84， 2011)，旨在使用优雅的参数化来测试与广义相对论的一致性 for modeling the dark energy at different times in the universes evolution.  My students 我和德克萨斯大学达拉斯分校的DARKLIGHT小组合作 Osservatorio Astronomico di Brera and also use the Texas Advanced Computing Center (TACC)在德克萨斯大学奥斯汀分校进行这些测试，我们有 own cluster of computing nodes on the UD campus.   In all cases, not only do the students learn how to use HPC to efficiently test dark energy models, but they also learned about HPC in general through usage and design of an instructive computing cluster built by the students from repurposed materials in the department.  In order to bridge 本科教育与科研的差距，需要本科生的经验 in HPC.  Beyond simply logging into a remote terminal, truly understanding HPC is 由于高性能计算集群的组成，对本科生来说尤其困难 of large machines locked-away in secure datacenters, offers few opportunities for students to grasp the totality of HPC systems.  A hands-on experience is critical to filling in the gaps in their understanding.

除了我的宇宙学研究之外，我还与特拉华大学有跨学科项目 Biology Department. We have successfully developed a novel physical model of the human head and brain for studying concussive and sub-concussive level collisions. There is also new work with Dr. Stenesen on developing methods to detect the electrical 果蝇眼睛中的信号和原子力显微镜的图像结构 and X-ray Computed Tomography (CT) scans, see the work on the student research webpage.

Peer-reviewed Publications:

1. “Exploring the constraints on cosmological models using JM, Francis Cavanna, William O 'toole, William Zimmerman, JCAP11(2018)011， arxiv:1801.01781.
2. “The Cosmic Acceleration of the Universe Lab using CosmoEJS Package” by JM, Open Source Physics Lab (2018). Open Source Physics website.
3. Modern Cosmology: Interactive Computer Simulations using Recent Observational Data Sets, JM, Larry Engelhardt, Keenan Stone, Ezekiel Shuler, Am. Jour. Phys., Vol. 81, Issue 6, 2013
4. 在宇宙尺度上检验广义相对论:实现和参数相关性, formerly, Testing General Relativity at Cosmological Scales using ISiTGR, Jason Dossett, Mustapha Ishak, JM, Phys. Rev. D, October 2011, arxiv:1109.4583.
5. Supernova, BAO, and CMB surface distance constraints on f(G) higher order gravity models, JM, Mustapha Ishak, John Thompson, Damien Easson, Phys.Rev.D81:063514,(2010), arxiv:1004.2459.
6. 一个最小不变量集作为高阶重力模型的系统方法:物理 and Cosmological Constraints, JM, Mustapha Ishak, JCAP 0912:020 (2009) arxiv:0912.5332.
7. 宇宙常数/相对论弯曲暗能量的一个新的独立极限 of Light by Galaxies and Clusters of Galaxies， Mustapha Ishak, Wolfgang Rindler, Jason Dossett, JM, Chris Allison, MNRAS 388, 1279-1283 (2008), arxiv:0710.4726.

Texas Symposium on Relativistic Astrophysics Meeting, 30-minute Contributed Talk: “用CosmoEJS探索哈勃恒定张力”，JM, 2019年12月16日，朴茨茅斯 England

达拉斯县社区学院山景校区物理研讨会空间周， 特邀演讲:“引力波、暗物质、暗能量:近期的成功与不足” of General Relativity”, JM, October 7, 2019

2019测试重力会议，贡献海报，宇宙模型的动力学 using CosmoEJS”, JM, January 17, 2019

达拉斯县社区学院山景校区物理研讨会空间周， 特邀演讲:“引力波、暗物质、暗能量:近期的成功与不足” of General Relativity”, JM, October 10, 2018

美国物理学会四月会议，贡献演讲:“宇宙学动力学。 models using CosmoEJS”, JM, Andrew Chang, April 16, 2018, Columbus, OH

TSAPS, San Antonio College, Contributed Talk: 平移和角加速度在一个新的物理模型中测量 a human head”, JM, Stephen Slaughter, Cora Keil, Sydney McCloskey, Andrew Chang, James Frisby, March 9, 2017, San Antonio, TX

Physics Colloquium, Dallas County Community College Mountain View Campus, Invited Talk: 引力波，暗物质，暗能量:最近的成功与不足 General Relativity”, JM, November 3, 2016, Dallas, TX

Physics Colloquium, The University of Texas at Dallas, Invited Talk: “计算宇宙学:模型和模拟能告诉我们关于宇宙的什么?”, JM, April 13, 2016, Richardson, TX

Physics Colloquium, Dallas County Community College Richland Campus, Invited Talk: 引力波，暗物质，暗能量:最近的成功与不足 General Relativity”, JM, March 4, 2016, Richardson, TX

Physics Colloquium, Dallas County Community College Mountain View Campus, Invited Talk: 引力波，暗物质，暗能量:最近的成功与不足 General Relativity”, JM, March 3, 2016, Dallas, TX

德克萨斯州相对论天体物理学研讨会，演讲和海报展示:“探索 宇宙学模型参数值的结果与CosmoEJS，一个交互 宇宙学Java模拟包”，JM, Francis Cavanna, William O 'toole, William Zimmerman, Geneva, Switzerland, December 13-18, 2015

美国天文学会德克萨斯州分会会议，演讲:“使用CosmoEJS研究宇宙学参数， 一个宇宙学Java模拟的交互式包”，JM, Francis Cavanna, William O’toole, William Zimmerman, University of Baylor, Waco, TX, October 29-31, 2015

Testing Gravity 2015, Talk: 利用宇宙ejs最新数据集对宇宙学模型进行交互测试 Package, JM, William Zimmerman (UD student), Vancouver, BC, January 14-17, 2015.

Texas Section APS Meeting, Talk: 交互式宇宙学建模与简单的Java模拟:从一个新的约束 Growth of Structure Module of CosmoEJS, JM, William Zimmerman (UD Student), College Station, TX, October 17-19, 2014.

赞助科林学院本科生跨学科研究会议 senior thesis presentation, Hawking Radiation: The Black Hole Destroyer, Aaron Stolle (UD student), Jacob Moldenhauer, Plano, TX, April 16-17, 2014.

50th Texas Symposium for Relativity and Astrophysics, Poster: Interactive Cosmological Modeling with Easy Java Simulations, Dallas, TX, December 8-13, 2013.

American Astronomical Society 221 Winter meeting, Talk: 交互宇宙学数据拟合模拟:对宇宙ejs的进一步研究, JM, & 赞助的学生海报，关于宇宙的交互式计算机模拟，海报: Modifications to CosmoEJS, Keenan Stone, Ezekiel Shuler, JM, Long Beach, CA, January 6-10, 2013.