Niels Bohr (1885-1962) was a Danish physicist who played a key role in the development of atomic theory and quantum mechanics, he was awarded the Nobel Prize for Physics in 1922. First published in 1924, this concise volume provides an English translation of a 1923 German language essay which appeared in the Zeitschrift fur Physik journal. It concerns itself with the fundamental postulates of quantum theory, aiming to present the principles of the theory in such a way that their application appears free from contradiction. This book will be of value to anyone with an interest in Bohr's contribution to physics.

This book focuses on new experimental and theoretical advances concerning the role of strange and heavy-flavour quarks in high-energy heavy-ion collisions and in astrophysical phenomena. The topics covered include * Strangeness and heavy-quark production in nuclear collisions and hadronic interactions, * Hadron resonances in the strongly-coupled partonic and hadronic medium, * Bulk matter phenomena associated with strange and heavy quarks, * QCD phase structure, * Collectivity in small systems, * Strangeness in astrophysics,* Open questions and new developments.

No scientific theory has caused more puzzlement and confusion than quantum theory. Physics is supposed to help us to understand the world, but quantum theory makes it seem a very strange place. This book is about how mathematical innovation can help us gain deeper insight into the structure of the physical world. Chapters by top researchers in the mathematical foundations of physics explore new ideas, especially novel mathematical concepts, at the cutting edge of future physics. These creative developments in mathematics may catalyze the advances that enable us to understand our current physical theories, especially quantum theory. The authors bring diverse perspectives, unified only by the attempt to introduce fresh concepts that will open up new vistas in our understanding of future physics.

The discovery in 2012 of the Higgs boson at the Large Hadron Collider (LHC) represents a milestone for the Standard Model (SM) of particle physics. Most of the SM Higgs production and decay rates have been measured at the LHC with increased precision. However, despite its experimental success, the SM is known to be only an effective manifestation of a more fundamental description of nature. The scientific research at the LHC is strongly focused on extending the SM by searching, directly or indirectly, for indications of New Physics. The extensive physics program requires increasingly advanced computational and algorithmic techniques. In the last decades, Machine Learning (ML) methods have made a prominent appearance in the field of particle physics, and promise to address many challenges faced by the LHC. This thesis presents the analysis that led to the observation of the SM Higgs boson decay into pairs of bottom quarks. The analysis exploits the production of a Higgs boson associated with a vector boson whose signatures enable efficient triggering and powerful background reduction. The main strategy to maximise the signal sensitivity is based on a multivariate approach. The analysis is performed on a dataset corresponding to a luminosity of 79.8/fb collected by the ATLAS experiment during Run-2 at a centre-of-mass energy of 13 TeV. An excess of events over the expected background is found with an observed (expected) significance of 4.9 (4.3) standard deviation. A combination with results from other \Hbb searches provides an observed (expected) significance of 5.4 (5.5). The corresponding ratio between the signal yield and the SM expectation is 1.01 +- 0.12 (stat.)+ 0.16-0.15(syst.). The 'observation' analysis was further extended to provide a finer interpretation of the V H(H bb) signal measurement. The cross sections for the VH production times the H bb branching ratio have been measured in exclusive regions of phase space. These measurements are used to search for possible deviations from the SM with an effective field theory approach, based on anomalous couplings of the Higgs boson. The results of the cross-section measurements, as well as the constraining of the operators that affect the couplings of the Higgs boson to the vector boson and the bottom quarks, have been documented and discussed in this thesis. This thesis also describes a novel technique for the fast simulation of the forward calorimeter response, based on similarity search methods. Such techniques constitute a branch of ML and include clustering and indexing methods that enable quick and efficient searches for vectors similar to each other. The new simulation approach provides optimal results in terms of detector resolution response and reduces the computational requirements of a standard particles simulation.

This book presents proton-3He elastic scattering experiments conducted at intermediate energies, with the aim of identifying three-nucleon force (3NF) effects in a four-nucleon scattering system. The 3NF plays an essential part in understanding various nuclear phenomena, and few-nucleon scatterings further offers a good opportunity to study the dynamical aspects of 3NFs. In particular, proton-3He scattering is one of the most promising approaches to an iso-spin dependence of 3NFs. The book in-depth explains the achieved development of polarized 3He target system for the proton-3He scattering experiments, and describes successful precise evaluation of the target polarization. The experiments yielded the first precise data for this system and offer a valuable resource for the study of 3NFs.

This book explores the prospects of rivaling ontological and epistemic interpretations of quantum mechanics (QM). It concludes with a suggestion for how to interpret QM from an epistemological point of view and with a Kantian touch. It thus refines, extends, and combines existing approaches in a similar direction. The author first looks at current, hotly debated ontological interpretations. These include hidden variables-approaches, Bohmian mechanics, collapse interpretations, and the many worlds interpretation. He demonstrates why none of these ontological interpretations can claim to be the clear winner amongst its rivals. Next, coverage explores the possibility of interpreting QM in terms of knowledge but without the assumption of hidden variables. It examines QBism as well as Healey's pragmatist view. The author finds both interpretations or programs appealing, but still wanting in certain respects. As a result, he then goes on to advance a genuine proposal as to how to interpret QM from the perspective of an internal realism in the sense of Putnam and Kant. The book also includes two philosophical interludes. One details the notions of probability and realism. The other highlights the connections between the notions of locality, causality, and reality in the context of violations of Bell-type inequalities.

This text presents an algebraic approach to the construction of several important families of quantum codes derived from classical codes by applying the well-known Calderbank-Shor-Steane (CSS), Hermitian, and Steane enlargement constructions to certain classes of classical codes. In addition, the book presents families of asymmetric quantum codes with good parameters and provides a detailed description of the procedures adopted to construct families of asymmetric quantum convolutional codes.Featuring accessible language and clear explanations, the book is suitable for use in advanced undergraduate and graduate courses as well as for self-guided study and reference. It provides an expert introduction to algebraic techniques of code construction and, because all of the constructions are performed algebraically, it enables the reader to construct families of codes, rather than only codes with specific parameters. The text offers an abundance of worked examples, exercises, and open-ended problems to motivate the reader to further investigate this rich area of inquiry. End-of-chapter summaries and a glossary of key terms allow for easy review and reference.

Providing a self contained step by step explanation, this book will guide the reader with a basic knowledge of quantum mechanics, to a sufficiently comprehensive level as well as to the frontier of contemporary physics. For the last two decades there has been a ceaseless growth of the area where the path integral (PI) method plays an important role: the main reasons are its intuitive aspect and ease of handling. However, this has raised questions elsewhere and in this book fundamental issues are resolved by starting from the canonical operator formalism to lead the reader to a more comprehensive level. Containing the most recent topics such as the lattice fermion problem in quantum field theory as well as the quantum Monte Carlo method in statistical mechanics this book will suit graduate students of quantum physics.

This book covers important concepts and applications of contemporary physics. The book emphasizes logical development of the subject and attempts to maintain rigor in the analytical discussions. The text has been presented in a concise and lucid manner. A modern description of properties and interaction of particle is given along with discussions on topics such as cosmology, laser and applications. The concepts are illustrated by numerous worked examples. Selected problems given at the end of each chapter help students to evaluate their skills. The book with its simple style, comprehensive and up-to-date coverage is highly useful for physics students. The detailed coverage and pedagogical tools make this an ideal book also for the engineering students studying core courses in physics.

We were created on the outer edge of the universe, and powerful ancients continue to watch us from that home far away. The ancients use 100% of their brains, which enables them to perform fantastic feats no earthly creature could imagine. Many years ago, these ancient beings altered the human DNA, removing our capability to use 100% of our brains, therefore keeping us forever beneath their reign and keeping them forever safe from human attack. Despite the lessened use of our brains, the human race has developed high-tech radar devices that travel into space, searching for intelligent life. The ancients have become aware of this technology; they are now concerned that humans have advanced enough to bring war. In an effort to avoid the inevitable, the ancients are coming to Earth to destroy the human race. Extermination is eminent, until Earth connects with its "sister planet." Together, the humans must fight back against this ancient power that seeks to destroy. The Outer Edge is not merely science fiction; it is an authoritative vision of our living universe. These fictional tribulations have direct and irrefutable links to science. And so the question remains: is science fiction truly fiction at all, or does it peer into the depths of fact and foreshadow devastation yet to come? Decipher the true riddles of the universe with The Outter Edge.

Presents the current view of quantum biology Presents central topics via introductory anecdotes Combines scientifically correct explanations and a popular language Demystifies quantum physics Provides standard and most recent references and recommended reading Includes a dictionary explaining central concepts

With applications in quantum field theory, general relativity and elementary particle physics, this four-volume work studies the invariance of differential operators under Lie algebras, quantum groups and superalgebras. This third volume covers supersymmetry, including detailed coverage of conformal supersymmetry in four and some higher dimensions, furthermore quantum superalgebras are also considered. Contents Lie superalgebras Conformal supersymmetry in 4D Examples of conformal supersymmetry for D > 4 Quantum superalgebras

It is not intuitive to accept that there exists a link between quantum physical systems and cognitive systems. However, recent research has shown that cognitive systems and collective (social) systems, including biology, exhibit uncertainty which can be successfully modelled with quantum probability. The use of such probability allows for the modelling of situations which typically violate the laws of classical probability. The Palgrave Handbook of Quantum Models in Social Science is is a unique volume that brings together contributions from leading experts on key topics in this new and emerging field. Completely self-contained, it begins with an introductory section which gathers all the fundamental notions required to be able to understand later chapters. The handbook then moves on to address some of the latest research and applications for quantum methods in social science disciplines, including economics, politics and psychology. It begins with the issue of how the quantum mechanical framework can be applied to economics. Chapters devoted to this topic range from how Fisher information can be argued to play a role in economics, to the foundations and application of quantum game theory. The handbook then progresses in considering how belief states can be updated with the theory of quantum measurements (and also with more general methods). The practical use of the Hilbert space (and Fock space) in decision theory is then introduced, and open quantum systems are also considered. The handbook also treats a model of neural oscillators that reproduces some of the features of quantum cognition. Other contributions delve into causal reasoning using quantum Bayes nets and the role of quantum probability in modelling so called affective evaluation. The handbook is rounded off with two chapters which discuss the grand challenges which lie ahead of us. How can the quantum formalism be justified in social science and is the traditional quantum formalism too restrictive? Finally, a question is posed: whether there is a necessary role for quantum mathematical models to go beyond physics. This book will bring the latest and most cutting edge research on quantum theory to social science disciplines. Students and researchers across the discipline, as well as those in the fields of physics and mathematics will welcome this important addition to the literature.

The Physical World offers a grand vision of the essential unity of physics that will enable the reader to see the world through the eyes of a physicist and understand their thinking. The text follows Einstein's dictum that 'explanations should be made as simple as possible, but no simpler', to give an honest account of how modern physicists understand their subject, including the shortcomings of current theory. The result is an up-to-date and engaging portrait of physics that contains concise derivations of the important results in a style where every step in a derivation is clearly explained, so that anyone with the appropriate mathematical skills will find the text easy to digest. It is over half a century since The Feynman Lectures in Physics were published. A new authoritative account of fundamental physics covering all branches of the subject is now well overdue. The Physical World has been written to satisfy this need. The book concentrates on the conceptual principles of each branch of physics and shows how they fit together to form a coherent whole. Emphasis is placed on the use of variational principles in physics, and in particular the principle of least action, an approach that lies at the heart of modern theoretical physics, but has been neglected in most introductory accounts of the subject.

Recent work in quantum information science has produced a revolution in our understanding of quantum entanglement. Scientists now view entanglement as a physical resource with many important applications. These range from quantum computers, which would be able to compute exponentially faster than classical computers, to quantum cryptographic techniques, which could provide unbreakable codes for the transfer of secret information over public channels. These important advances in the study of quantum entanglement and information touch on deep foundational issues in both physics and philosophy. This interdisciplinary volume brings together fourteen of the world's leading physicists and philosophers of physics to address the most important developments and debates in this exciting area of research. It offers a broad spectrum of approaches to resolving deep foundational challenges - philosophical, mathematical, and physical - raised by quantum information, quantum processing, and entanglement. This book is ideal for historians, philosophers of science and physicists.

The international bestseller from the author of Breakfast with Einstein Emmy is no ordinary dog. When adopted from the shelter by physics professor Chad Orzel, she becomes immediately fascinated by his work. Could she use quantum tunnelling to get through the neighbour's fence? How about diffracting round a tree to chase squirrels? Or using virtual particles to catch bunnies made of cheese? Taking Emmy's anarchic behaviour as a starting point, Orzel explains the key theories of quantum physics. From quarks and gluons to Heisenberg's uncertainty principle, this is a uniquely entertaining way to unlock the secrets of the universe.

Strong Interactions in Spacelike and Timelike Domains: Dispersive Approach provides the theoretical basis for the description of the strong interactions in the spacelike and timelike domains. The book primarily focuses on the hadronic vacuum polarization function, R-ratio of electron-positron annihilation into hadrons, and the Adler function, which govern a variety of the strong interaction processes at various energy scales. Specifically, the book presents the essentials of the dispersion relations for these functions, recaps their perturbative calculation, and delineates the dispersively improved perturbation theory. The book also elucidates the peculiarities of the continuation of the spacelike perturbative results into the timelike domain, which is indispensable for the studies of electron-positron annihilation into hadrons and the related processes.

Perturbation theory is a powerful tool for solving a wide variety of problems in applied mathematics, a tool particularly useful in quantum mechanics and chemistry. Although most books on these subjects include a section offering an overview of perturbation theory, few, if any, take a practical approach that addresses its actual implementation Introduction to Perturbation Theory in Quantum Mechanics does. It collects into a single source most of the techniques for applying the theory to the solution of particular problems. Concentrating on problems that allow exact analytical solutions of the perturbation equations, the book resorts to numerical results only when necessary to illustrate and complement important features of the theory. The author also compares different methods by applying them to the same models so that readers clearly understand why one technique may be preferred over another. Demonstrating the application of similar techniques in quantum and classical mechanics, Introduction to Perturbation Theory in Quantum Mechanics reveals the underlying mathematics in seemingly different problems. It includes many illustrative examples that facilitate the understanding of theoretical concepts, and provides a source of ideas for many original research projects.

This work provides a convincing motivation for and introduction to magnon-based computing. The challenges faced by the conventional semiconductor-transistor-based computing industry are contrasted with the many exciting avenues for developing spin waves (or magnons) as a complementary technology wherein information can be encoded, transmitted, and operated upon: essential ingredients for any computing paradigm. From this general foundation, one particular operation is examined: phase conjugation via four-wave-mixing (FWM). The author constructs an original theory describing the generation of a phase conjugate mirror with the remarkable property that any incident spin wave will be reflected back along the same direction of travel. After establishing a theoretical framework, the careful design of the experiment is presented, followed by the demonstration of a magnetic phase conjugate mirror using four-wave mixing for the first time. The thesis concludes with an investigation into the unexpected fractal behaviour observed arising from the phase conjugate mirror - a result that is testament to the richness and vibrancy of these highly nonlinear spin wave systems.

Path integrals provide a powerful method for describing quantum phenomena. This book introduces the quantum mechanics of particles that move in curved space by employing path integrals and then using them to compute anomalies in quantum field theories. The authors start by deriving path integrals for particles moving in curved space and their supersymmetric generalizations. They then discuss the regularization schemes essential to constructing and computing these path integrals. This topic is used to introduce regularization and renormalization in quantum field theories in a wider context. These methods are then applied to discuss and calculate anomalies in quantum field theory. Such anomalies provide enormous constraints in the search for physical theories of elementary particles, quantum gravity and string theories. An advanced text for researchers and graduate students of quantum field theory and string theory, the first part is also a stand-alone introduction to path integrals in quantum mechanics.

In this thesis we discuss the construction of an effective field theory (EFT) for non-relativistic Majorana fermions, show how to use it to calculate observables in a thermal medium, and derive the effects of these thermal particles on the CP asymmetry. The methods described in this thesis allow a systematic and effective description of the non-relativistic dynamics of a heavy Majorana fermion at finite temperature. The CP asymmetry is studied for hierarchical and nearly degenerate heavy-neutrino masses and the analysis includes the treatment of lepton-flavor effects. Heavy Majorana neutrinos are involved in many scenarios of physics beyond the standard model and, in the leptogenesis framework, they are at the root of the baryon asymmetry in the Universe. Besides simplifying exist in g results, the EFT approach provides useful tools for addressing even more involved observables. Indeed, taken together, the approach and the material presented here represent an important step toward a systematic improvement of our knowledge of the CP asymmetry in heavy-neutrino decays at finite temperature.

The energy momentum tensor (EMT) is one of the most fundamental observables in physics. Recently, a novel method to define EMT on the basis of the gradient-flow formalism has been proposed. It turned out that the EMT operator can be constructed even on the lattice with the method, which enables non-perturbative computations. This approach has been successfully applied to the analyses on thermodynamic quantities. This book presents the study on spatial EMT distributions around static charges via the gradient flow in lattice simulations based on SU(3) Yang-Mills theory. Static charges are employed as probes to explore complex quantum systems, and EMT then characterizes the response of vacuum as well as hot medium under the existence of the charges, which significantly provides profound and novel insights into the non-perturbative phenomena, such as the confinement of quarks. In addition, the book treats the study on the EMT distribution around a magnetic vortex in the Abelian-Higgs model, which is compared with the lattice result. These achievements open up various future studies for revealing non-trivial aspects of the strong interaction. The book also includes well-organized reviews on general properties of EMT, lattice gauge theory and the gradient-flow formalism with its application to the definition of EMT. They are useful for students and young researchers as a brief introduction to this field.

E = mc2 and the Periodic Table . . .

RELATIVISTIC EFFECTS IN CHEMISTRY

This century's most famous equation, Einstein's special theory of relativity, transformed our comprehension of the nature of time and matter. Today, making use of the theory in a relativistic analysis of heavy molecules, that is, computing the properties and nature of electrons, is the work of chemists intent on exploring the mysteries of minute particles.

The first work of its kind, Relativistic Effects in Chemistry details the computational and analytical methods used in studying the relativistic effects in chemical bonding as well as the spectroscopic properties of molecules containing very heavy atoms. The second of two independent volumes, Part B: Applications contains specific experimental and theoretical results on the electronic states of molecules containing very heavy atoms as well as their spectroscopic properties and electronic structures. The first one-volume catalog of comprehensive computational results, Part B details:

• the relativistic effects on the electronic structure of transition metal clusters, such as the Cu, Ag, and Au triad
• the electronic structure of open-shell transition metal clusters such as Rh3 and Ir3
• the electronic and spectroscopic properties of heteronuclear diatomics of main group p-block elements from Ga to Po, especially the diatomic hydrides, halides, and chalconides
• the clusters of the very heavy main group p-block elements from Ga to Po
• the relativistic effects on molecules containing lanthanide and actinide atoms, including metals inside fullerenes.

An extraordinary new examination of Periodic Table elements, Part B of Relativistic Effects in Chemistry is also evidence of the enduring influence of Einstein's revolutionary theory.

The book describes state-of-the-art advances in simulators and emulators for quantum computing. It introduces the main concepts of quantum computing, defining q-bits, explaining the parallelism behind any quantum computation, describing measurement of the quantum state of information and explaining the process of quantum bit entanglement, collapsed state and cloning. The book reviews the concept of quantum unitary, binary and ternary quantum operators as well as the computation implied by each operator. It provides details of the quantum processor, providing its architecture, which is validated via execution simulation of some quantum instructions.