Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThe Quantum Field Theory on Which the Everyday World Supervenes
126
0
0.0
(
0
)
Authors
Sean M. Carroll
Ask ChatGPT about the research
No Arabic abstract
Effective Field Theory (EFT) is the successful paradigm underlying modern theoretical physics, including the Core Theory of the Standard Model of particle physics plus Einsteins general relativity. I will argue that EFT grants us a unique insight: each EFT model comes with a built-in specification of its domain of applicability. Hence, once a model is tested within some domain (of energies and interaction strengths), we can be confident that it will continue to be accurate within that domain. Currently, the Core Theory has been tested in regimes that include all of the energy scales relevant to the physics of everyday life (biology, chemistry, technology, etc.). Therefore, we have reason to be confident that the laws of physics underlying the phenomena of everyday life are completely known.
rate research
Read More
Effective Field Theories have been used successfully to provide a bottom-up description of phenomena whose intrinsic degrees of freedom behave at length scales far different from their effective degrees of freedom. An example is the emergent phenomenon of bound nuclei, whose constituents are neutrons and protons, which in turn are themselves composed of more fundamental particles called quarks and gluons. In going from a fundamental description that utilizes quarks and gluons to an effective field theory description of nuclei, the length scales traversed span at least two orders of magnitude. In this article we provide an Effective Field Theory viewpoint on the topic of emergence, arguing on the side of reductionism and weak emergence. We comment on Andersons interpretation of constructionism and its connection to strong emergence.
We review the physics at the end of the nineteenth century and summarize the process of the establishment of Special Relativity by Albert Einstein in brief. Following in the giants footsteps, we outline the scientific method which helps to do research. We give some examples in illustration of this method. We discuss the origin of quantum physics and string theory in its early years of development. The discoveries of the neutrino and the correct model of solar system are also present.
We adopt in this work the idea that the building blocks of the visible Universe belong to a class of the irreducible representations of the Poincare group of transformations (the things) endowed with classificatory quantum numbers (the properties). After a discussion of this fundamentality, the question of the nature of both dark components of the Universe which are deemed necessary, but have not been observed, is analyzed within this context. We broadly discuss the ontology of dark matter/dark energy in relation to the irreducible representations of the Poincare group + quantum numbers, pointing out some cases in which the candidates can be associated to them, and others for which a reclassification of both the dark and visible (ordinary) components would be needed.
I propose a new class of interpretations, {it real world interpretations}, of the quantum theory of closed systems. These interpretations postulate a preferred factorization of Hilbert space and preferred projective measurements on one factor. They give a mathematical characterisation of the different possible worlds arising in an evolving closed quantum system, in which each possible world corresponds to a (generally mixed) evolving quantum state. In a realistic model, the states corresponding to different worlds should be expected to tend towards orthogonality as different possible quasiclassical structures emerge or as measurement-like interactions produce different classical outcomes. However, as the worlds have a precise mathematical definition, real world interpretations need no definition of quasiclassicality, measurement, or other concepts whose imprecision is problematic in other interpretational approaches. It is natural to postulate that precisely one world is chosen randomly, using the natural probability distribution, as the world realised in Nature, and that this worlds mathematical characterisation is a complete description of reality.
Mean-field analysis is an important tool for understanding dynamics on complex networks. However, surprisingly little attention has been paid to the question of whether mean-field predictions are accurate, and this is particularly true for real-world networks with clustering and modular structure. In this paper, we compare mean-field predictions to numerical simulation results for dynamical processes running on 21 real-world networks and demonstrate that the accuracy of the theory depends not only on the mean degree of the networks but also on the mean first-neighbor degree. We show that mean-field theory can give (unexpectedly) accurate results for certain dynamics on disassortative real-world networks even when the mean degree is as low as 4.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
