CMB as a Probe of New Physics and Old Times Thesis by Vera Gluˇsˇcevi´c In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy California Institute of Technology Pasadena, California 2013 (Submitted February 28, 2013) ii c 2013 Vera Gluˇsˇcevi´c All Rights Reserved iii To Tim, the love of my life, and to Babyo, for the best-ever kicks of support that enabled the completion of this thesis. iv \The vastness of the heavens stretches my imagination|stuck on this carousel my little eye can catch one-million-year-old light. A vast pattern|of which I am a part... What is the pattern or the meaning or the why? It does not do harm to the mystery to know a little more about it. For far more marvelous is the truth than any artists of the past imagined it..." | Footnote, Richard Feynman \I come in search of the truth." | The Star Trek series: Where Silence Has Lease, Q v Acknowledgements \It is the act of understanding this beautiful Universe that bids our minds run so wild|perhaps one of the highest pleasures of life... but Love is the giver of life and meaning, and stands marvelous at the source of it all..." The Universe is beautiful. My road from Serbia, around the world, and to the United States has taught me that very few people are in a position to earn a living on a passion of understanding beauty. The incredibly lucky situation I am in as a cosmologist I owe to those in this country who recognize and generously support the value of scientific research, to the existence of the extraordinary place that is Caltech, and to the decisions of the admissions committee and my adviser Marc Kamionkowski to support me as a graduate student. I am particularly indebted to Marc for allowing me to benefit from his ability to provide excellent guidance and insight in matters of research and academic navigation, completely devoid of judgment and personal bias, and especially to give time for a student to learn at her own pace and in her own manner, while staying readily available to offer advice at all times. His capacity to abstract the most relevant, to see the solution long before beginning the \hard work," and his intuition for where the interesting questions lie, remain an inspiration and a goal of my own professional future. I also had the good fortune to be co-advised by Chris Hirata in the last two years. Chris is a rare individual whose astonishing breadth and depth of understanding all things physics, and readiness to make as much time as one can desire for infinitely patient explanations, is perhaps only surpassed by his unassuming humility and his kindness to those around him. I am truly privileged and humbled to be among the people who have a chance to work with him. In addition, I would like to express gratitude to Annika Peter for leading me into the world of dark-matter research and being the saving voice of encouragement and support at times when I most needed it. I wouldn't have made it through my last few years at Caltech had it not been for this voice. I am very grateful to my collaborators, Robert Caldwell, Asantha Cooray, and Rennan Barkana, for sharing the excitement of research with me, expanding my experience into their areas of expertise, and providing advice and support along the way. I am especially lucky to have had a chance to work closely with Duncan Hanson and experience his committed tutoring on data analysis and vi Python, which now constitute life ingredients for my research, and also thankful for many fun and intellectually challenging conversations we had in the past year. Finally, many thanks to Sean Carroll for enlightening conversations on cosmic birefringence! My enjoyment of learning was abundantly rewarded at Caltech by a number of lecturers in the Physics Department whom I wish to thank for their devotion and excellence in teaching. Also, had it not been for the many Caltech staff who are able and willing to sweep away all sorts of problems efficiently as if they never existed, life in graduate school would not have been half the sheltered fun that it was. Many other people have sustained me, academically and in life, throughout my years at Caltech, or otherwise have contributed to laying out the road that led me to complete my doctoral work. Some of those whose influence was most striking I mention here. Thinking back to the fun times at Caltech, several groups of dear, dear people immeditately come to mind. My classmates: Gwen, Drew, Tucker, Sam, Mike, Tim, Krzysztof, and Elisabeth|guys, thanks so much for pushing together through the challenges of the first year; it's no exaggeration to say I wouldn't have made it (many times over) without you. \The Physicists": Evan, Itamar, Ron, Kevin, Brian, Paula, Laura, M'hair, Jasper, Milivoje, Dan, and others|you are the smartest and funnest (and funniest!) group of troopers I mingled with; it was a great joy being around you, from our late-night problem-solving sessions at the SFL, all the way through all those games, nerdy discussions, and trips we did together. I now somehow need to deal with the hole that's left in my life since we all started graduating. For mentoring, presenting me with role models to look up to, and giving golden advice at crucial times, several senior grad students are especially responsible: Adrienne, Dan, Yacine, and Tristan. Also, thanks to all fellow TAPIRs for sharing Thursday \lunch and enlightenment" and pride in being a theorist! Finally, the St. James' family, in particular Rev. Anne Tumilty, Rev. Jon Dephouse, the Choir, and the 20s{30s crowd, whose loving support has carried me through both happy and challenging times|many thanks for the overflow of grace from you folks. Crucial additions to my education were the summer schools, conferences, and workshops I attended|I am very much in debt to the organizers of these events as well as to the participants (many of whom became dear friends), for the life-changing experiences they brought. Especially dear to my heart was the STScI Summer Program of 2006, where my adventure in US-based astronomy began. Dave Soderbloom, Daniela Calzetti, and Mario Livio|you have quite literally altered the course of my career and life. There are two people to whom I owe much for being my unofficial advisers at various stages in my career: Milan Cirkovi´c,during´ my very first scientific beginnings in Belgrade's X High School, and Dragan Huterer, whose dear friendship and continuous support were a boost all along this road. Many teachers throughout my life inspired sparks of the passion for knowledge, but especially vii Prof. Dostani´cwho introduced me to the impeccable elegance of proof-based mathematics, and my Serbian teacher Milica Opaˇci´c,who taught me how logical thinking enbodied and adorned in words can make for a thrilling kind of beauty. Folks at the Public Observatory and Planetarium in Belgrade, Goran, Mi´ca,Otaˇs,Bane, and others, opened wide the doors of astronomy for me during my high-school years by teaching courses for the public and by letting us get a closer peek into the night sky. I was hooked to astrophysics ever since. Otaˇse:even after having heard many of the best lecturers this world has to offer, I still think you belong on the list. Warm thanks also to my friends, the many pearls scattered around the world. Kvokane: I cherish the memory of being in your company while getting the hard work done for school. And Zverko: thanks for making me jealous enough to gather courage and take the Test to become a collaborator at the Belgrade Observatory|step one on this journey. Also, in principle, thanks for growing up with me and sharing my Beograd|such wonderous place to be free and dream a dream. Many roads start from home; mine too started with my family. I owe them my life and who I am today. My aunt Mirjana, who deserves a medal for the fiercest cheerer-on for all my successes. My dad who did a great job with igniting curiosity at a very early age when he showed me a flagellum through a microscope|the fire burned ever since. My grandmas and my grandpa, for the purest loving kindness since day zero (Eko: volela bih da si sad tu da bratski podelimo slavljeniˇcku ˇcokoladu dok mi se smejeˇsˇstosam ti postala \Doktor Filozofije”!). The Mortons, John, Dan, Roberta, Deborah, Rebecca, Bela: thanks, guys, for the many ways you supported me since you first met me; it truly is an honor to take up your name. Ron and Itamar: your friendship and unconditional love made Pasadena a home away from blood-family. And again, Itamar: I can never say all the thanks that would match what you did when you pushed me into the \easy-and-correct" physics way while I was still pondering if I'm cut out for this research thing, nor what you still do whenever I need some light along the way. And the very special thanks I keep for the end... To Mama, for shaping who I am, for supporting with every fiber of her being (and beyond) all my causes, and for selflessly and lovingly directing her many qualities I can only hope to acquire some day to the well-being of her child. To my husband Tim|my light, my strength, my team, my completion|for the Love such as I never dreamed existed, surpassing all words and worlds.