Quantum field theory has had a profound influence on mathematics, and on geometry in particular. However, the notorious difficulties of renormalization have made quantum field theory very inaccessible for mathematicians. This provides complete mathematical foundations for the theory of perturbative quantum field theory, based on Wilson's ideas of low-energy effective field theory and on the Batalin-Vilkovisky formalism.
There have been many recent and important developments based on effective field theory and the renormalization group in atomic, condensed matter, nuclear and high-energy physics. These powerful and versatile methods provide novel approaches to study complex and strongly interacting many-body systems in a controlled manner. The six extensive lectures gathered in this volume combine selected introductory and interdisciplinary presentations focused on recent applications of effective field theory and the renormalization group to many-body problems in such diverse fields as BEC, DFT, extreme matter, Fermi-liquid theory and gauge theories. Primarily aimed at graduate students and junior researchers, they offer an opportunity to explore fundamental physics across subfield boundaries at an early stage in their careers.
Effective models of strong and electroweak interactions are extensively applied in particle physics phenomenology, and in many instances can compete with large-scale numerical simulations of Standard Model physics. These contexts include but are not limited to providing indications for phase transitions and the nature of elementary excitations of strong and electroweak matter. A precondition for obtaining high-precision predictions is the application of some advanced functional techniques to the effective models, where the sensitivity of the results to the accurate choice of the input parameters is under control and the insensitivity to the actual choice of ultraviolet regulators is ensured. The credibility of such attempts ultimately requires a clean renormalization procedure and an error estimation due to a necessary truncation in the resummation procedure. In this concise primer we discuss systematically and in sufficient technical depth the features of a number of approximate methods, as applied to various effective models of chiral symmetry breaking in strong interactions and the BEH-mechanism of symmetry breaking in the electroweak theory. After introducing the basics of the functional integral formulation of quantum field theories and the derivation of different variants of the equations which determine the n-point functions, the text elaborates on the formulation of the optimized perturbation theory and the large-N expansion, as applied to the solution of these underlying equations in vacuum. The optimisation aspects of the 2PI approximation is discussed. Each of them is presented as a specific reorganisation of the weak coupling perturbation theory. The dimensional reduction of high temperature field theories is discussed from the same viewpoint. The renormalization program is described for each approach in detail and particular attention is paid to the appropriate interpretation of the notion of renormalization in the presence of the Landau singularity. Finally, results which emerge from the application of these techniques to the thermodynamics of strong and electroweak interactions are reviewed in detail.
A modern introduction to quantum field theory for graduates, providing intuitive, physical explanations supported by real-world applications and homework problems.
INSTANT NEW YORK TIMES BESTSELLER “Most appealing... technical accuracy and lightness of tone... Impeccable.”—Wall Street Journal “A porthole into another world.”—Scientific American “Brings science dissemination to a new level.”—Science The most trusted explainer of the most mind-boggling concepts pulls back the veil of mystery that has too long cloaked the most valuable building blocks of modern science. Sean Carroll, with his genius for making complex notions entertaining, presents in his uniquely lucid voice the fundamental ideas informing the modern physics of reality. Physics offers deep insights into the workings of the universe but those insights come in the form of equations that often look like gobbledygook. Sean Carroll shows that they are really like meaningful poems that can help us fly over sierras to discover a miraculous multidimensional landscape alive with radiant giants, warped space-time, and bewilderingly powerful forces. High school calculus is itself a centuries-old marvel as worthy of our gaze as the Mona Lisa. And it may come as a surprise the extent to which all our most cutting-edge ideas about black holes are built on the math calculus enables. No one else could so smoothly guide readers toward grasping the very equation Einstein used to describe his theory of general relativity. In the tradition of the legendary Richard Feynman lectures presented sixty years ago, this book is an inspiring, dazzling introduction to a way of seeing that will resonate across cultural and generational boundaries for many years to come.
This open access book... There is significant interest in the Philosophy of Science community to understand the role that "effective theories" have in the work of forefront science. The ideas of effective theories have been implicit in science for a long time, but have only been articulated well in the last few decades. Since Wilson's renormalization group revolution in the early 1970's, the science community has come to more fully understand its power, and by the mid-1990's it had gained its apotheosis. It is still one of the most powerful concepts in science, which has direct impact in how one thinks about and formulates theories of nature. It is this power that this Brief sets out to emphasize through historical analysis and current examples. This is an open access book.
This book is a broad-based text intended to help the growing student body interested in constructing and applying methods of effective field theory to solve problems in their research. It begins with a review of using symmetries to identify the relevant degrees of freedom in a problem, and then presents a variety of methods that can be used to construct various effective theories. A detailed discussion of canonical applications of effective field theory techniques with increasing complexity is given, including Fermi's weak interaction, heavy-quark effective theory, and soft-collinear effective theory. Applications of these techniques to study physics beyond the standard model, dark matter, and quantum and classical gravity are explored. Although most examples come from questions in high-energy physics, many of the methods can also be applied in condensed-matter settings. Appendices include various factoids from group theory and other topics that are used throughout the text, in an attempt to make the book self-contained.
"A Prelude to Quantum Field Theory offers a short introduction to quantum field theory (QFT), a powerful framework for understanding particle behavior that is an essential tool across many subfields of physics. A subject that is typically taught at the graduate level in most physics departments, quantum field theory is a unification of standard quantum theories and special relativity, which depicts all particles as "excitations" that arise in underlying fields. It extends quantum mechanics, the modern theory of one or few particles, in a way that is useful for the analysis of many-particle systems in the real world. As it requires a different style of thinking from quantum mechanics, which is typically the undergraduate physics student's first encounter with the quantum world, many beginners struggle with the transition to quantum field theory, especially when working with traditional textbooks. Existing books on the subject often tend to be large, sophisticated, and complete; and an overwhelming wealth of information and technical detail makes it difficult for the novice to discern what is most important. This book is a concise, friendly entrée for QFT-beginners, guiding the reader from the style of quantum mechanical thinking to that of QFT, and distilling the key ideas without a welter of unnecessary detail. In contrast with standard texts, which are predominantly particle physics-centric, this book is designed to be "subfield-neutral" - usable by students of any background and interest, and easily adaptable in a course setting according to instructors' preferences. The authors' conviction is that QFT is a core element of physics that should be understood by all PhD physicists-but that developing an appreciation for it does not require digesting a large, encyclopedic volume"--
