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Searching the Cosmos: Ripples from Avant-Garde Cosmological Probes

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Searching the Cosmos: Ripples from Avant-Garde Cosmological Probes Searching the Cosmos: Ripples from Avant-Garde Cosmological Probes Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Paulo Montero-Camacho, B.S., M.S. Graduate Program in Physics The Ohio State University 2019 Dissertation Committee: Christopher M. Hirata, Advisor Barbara Ryden Amy Conolly Eric Braaten c Copyright by Paulo Montero-Camacho 2019 Abstract The standard model of cosmology (ΛCDM model) makes several well-justified assumptions about the underlying physics involved in cosmology from the early Uni- verse up till now. Based on those assumptions the standard model of cosmology makes extremely precise, and successful, predictions about the physical properties of the Universe we live on. Even though the ΛCDM model of Cosmology has proved to be remarkably successful, there are still open questions. This thesis presents the work I have done to explore the relaxation of a few of those well-justified assumptions, in order to study the impact they could have on our current understanding of different cosmological probes. In Chapter 2, I consider possible sources - within the Physics Standard Model - of circular polarization in the Cosmic Microwave Background, and resolve the conflict between previous results in the literature. Chapter 3 shows the effects of inhomogeneous reionzation in the Lyman-α forest. Also it studies a first approach at mitigating these effects in near-future Lyman-α data. Finally, I discuss white dwarf star explosions as a constraining mechanism for primordial black holes as Dark Matter candidates in Chapter 4. ii to my friends, family, and especially to my partner on this journey and the next, Jiaxin iii Acknowledgments I have always been fascinated with learning about cool science and space. When I was a kid, I was interested in learning more about galaxies, stars and the solar system, I would spend a lot of time looking at the old encyclopedias we had in my parents home. I quite enjoyed the whole learning process, and I believe this gratification from the search for new knowledge lead me to my PhD in physics. In my time at the Scientific High School of Alajuela, I decided to pursue physics thanks to the wonderful guidance of my physics teacher, Pablo Blanco. However, it took half of my undergraduate career - with the advice of Francisco Frutos, Javier Bonatti and Rodrigo Carboni - to finally choose which area in physics I was going to dedicate my time to. I ended up choosing cosmology, because I was really fascinated by the standard model of cosmology. I will always be charmed by how in the beginning there was nothing, and then ... well then there was everything! My time at The Ohio State University and, in particular, at the Center for Cos- mology and AstroParticle Physics (CCAPP) has been amazing thanks to the friendly and supportive environment. I am thankful to my advisor Chris Hirata not only for being a great advisor and role model in these five years, but also for providing the right atmosphere to enhance the growth of my abilities as a researcher. I will miss our conversations not only because of his vast knowledge of cosmology but also because of how approachable, considerate and patient he is. iv These five years at The Ohio State University would have been very different without the support of my colleagues and friends. Xiao Fang and Daniel Martens, I am so glad we were office-mates, thank you for the constant support in the good times and the bad ones. Also, thank you for all the advice, discussions and for all the trips! Benjamin Buckman, I am grateful for having you as a friend, and your advice and suggestions have played a role in moving my research forward. To my current office-mates: Jahmour Givans and Daniella Roberts, thank you for the good times. To the members of my committee, Barbara Ryden, Amy Connolly and Eric Braaten, thank you for your guidance, but most importantly, thank you for your questions. My letter writers and collaborators Paul Martini and Klaus Honscheid, I am grateful for all the support and counseling. To Makana Silva, Chenxiao Zeng and Gabriel Vasquez, I thank you for your work on our projects, and I hope I did a good job advising you. To the other members of CCAPP, who make it a great place to do science, and have helped my growth one way or another. To Niall MacCrann, Ami Choi, Ashley Ross and Heidi Wu, thank you for being great postdocs and for asking great questions. To the other graduate students in CCAPP who I have enjoyed discussing with: Su- Jeong Lee, Bei Zhou, Matthew Digman, Heyang Long, Brian Clark and Hui Kong. Finally, to John Beacom and Annika Peter, thank you for being awesome role models. My family has also been a strong pillar during my studies. My father Carlos has always been interested in my research, and his engaging conversations have been the inspiration for how to overcome a few obstacles. My mother Jeannette taught me the need to be open-minded, and she is partially to blame for how much I enjoy teaching. And finally, to my brother Carlos Andr´es, his support was pivotal during v my application to graduate school, and it still is. Without you I would not have made it. I am also grateful to my friends outside of astrophysics. Ethel Perez and Emilio Codecido, who helped by distracting me from the stress. To my gaming and soccer buddies, Carlos Avila, Jorge Esquivel, Mariano Esquivel, Scarleth Morales, Alexander Sandoval and Pablo Sandoval; thank you for the great times, life would not be the same without you - but please stop getting married while I am so far away! To my partner in this journey, Jiaxin Wu, without whom my PhD would have been far worse and less enjoyable. I hope we continue making great memories in the years to come. To everyone I mentioned above, one way or another you have helped me greatly, and for that I thank you. This work would not have been possible without you. vi Vita 2013 . .B.S. University of Costa Rica 2016 ........................................M.S. The Ohio State University Publications Research Publications \Slowly Rotating Curzon-Chazy Metric" Montero-Camacho P., Frutos-Alfaro F., Gutierrez-Chaves C., Cordero-Garcia I. Revista de Matem´atica: Teor´ıa y Aplicaciones, Volume 22, Issue 2, 265-274 (2015) \Approximate Metric for a Rotating Deformed Mass" Frutos-Alfaro F., Montero-Camacho P., Araya M., Bonatti-Gonzalez J. International Journal of Astronomy and Astrophysics, Volume 5, Issue 1, 1-10 (2015) \Exploring Circular Polarization in the CMB due to Conventional Sources of Cosmic Birefringence" Montero-Camacho P., Hirata C. M. Journal of Cosmology and Astroparticle Physics, Volume 2018, Issue 08, 040 (2018) \Impact of Inhomogeneous Reionization in the Lyman α forest" Montero-Camacho P., Hirata C. M., Martini P., Honscheid− K. Monthly Notices of the Royal Astronomical Society, Volume 487, Issue 1, 1047-1056 (2019) Fields of Study Major Field: Physics vii Table of Contents Page Abstract....................................... ii Dedication...................................... iii Acknowledgments . iv Vita ......................................... vii ListofTables.................................... xi List of Figures . xii 1. Introduction..................................1 1.1 Cosmology 101 . .1 1.1.1 Statistical tools in modern cosmology . .7 1.2 Cosmic Microwave Background . .9 1.3 The Dark Ages and the epoch of reionization . 14 1.3.1 Lyman-α forest . 18 1.3.2 21 cm cosmology . 19 1.4 Dark Matter suspects . 21 1.5 Synopsisofthiswork.......................... 24 2. Exploring circular polarization in the CMB due to conventional sources of cosmic birefringence . 27 2.1 Introduction .............................. 28 2.2 General aspects of circular polarization . 33 2.3 Birefringence from spin polarized hydrogen atoms from the Cosmic Dawnepoch............................... 36 2.3.1 Order of magnitude . 39 viii 2.3.2 Detailed calculation . 41 2.4 Birefringence from spin polarized hydrogen atoms at recombination 50 2.4.1 Order of magnitude . 50 2.4.2 Detailed calculation . 53 2.5 Photon-photon scattering . 56 2.5.1 Order of magnitude . 56 2.5.2 Detailed calculation . 58 2.5.3 Comparison with previous calculations . 70 2.6 Static non-linear polarizability of hydrogen . 72 2.6.1 Order of magnitude . 72 2.6.2 Detailed computation . 73 2.7 Plasma delay: non-linear response of free electrons . 76 2.7.1 Order of magnitude . 77 2.7.2 Rigorous calculation . 77 2.8 Conclusion . 84 3. Impact of inhomogeneous reionization on the Lyman-α forest . 87 3.1 Introduction .............................. 88 3.2 Conventions and formalism . 93 3.3 Simulations ............................... 97 3.3.1 Smallboxes........................... 98 3.3.2 Largeboxes........................... 100 3.4 Assessment of contamination . 102 3.4.1 Linear power spectrum (3D) . 104 3.4.2 Computation of (zre) .................... 104 3.4.3 Cross-power spectrum of matter and ............ 105 3.4.4 Linear power spectrum (1D) . 109 3.5 Constraining the effect with 21 cm cosmology . 113 3.6 Discussion . 116 4. White Dwarf star survival in an PBH ocean . 120 4.1 Introduction .............................. 121 4.2 White Dwarf survival . 127 4.2.1 Velocity and density profiles . 128 4.2.2 Thermal effects on WD materials by a passing PBH . 130 4.2.3 Ignition and runaway explosion? . 135 4.2.4 Ignition rate and PBH constraints . 141 4.3 Conclusion . 147 ix 5. Conclusion................................... 148 Appendices 150 A. Circular polarization of the Cosmic Microwave Background . 150 A.1 Anisotropic 21 cm radiation in expanding media . 150 A.2 Irreducible components of the density matrix . 154 A.3 Special functions: Spherical harmonics . 155 A.4 Source term for polarized atoms from CMB anisotropies .
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