Recent Additions: New and Updated Entries in the Past 60 Days
Displaying entries 16 through 30 of 102 found.
Animate Cosmos > Quantum Cosmology > quantum CS
Berezutskii, Aleksandr, et al.
Probing Criticality in Quantum Spin Chains with Neural Networks.
A five person team based at the Deep Quantum Laboratory, Skolkovo Institute of Science, Moscow including Jacob Biamonte provide further insights into nature’s deep attraction to reside at an optimum critical poise even in the previously remote, fundamental depth.
The numerical emulation of quantum systems often requires an exponential number of degrees of freedom which translates to a computational bottleneck. Recent studies have revealed that neural networks are suitable for the determination of macroscopic phases of matter and associated phase transitions as well as efficient quantum state representation. In this work, we address quantum phase transitions in quantum spin chains and show that even neural networks with no hidden layers can be effectively trained to distinguish between magnetically ordered and disordered phases. Our results extend to a wide class of interacting quantum many-body systems and illustrate the wide applicability of neural networks to many-body quantum physics. (Abstract)
Animate Cosmos > Quantum Cosmology > quantum CS
The concept of deep learning has attracted dramatic interest over the last decade. First applied in the domain of image and natural speech recognition, algorithms for machine learning have recently shown their utility in statistical mechanics of interacting classical and quantum systems. (2) The application of machine learning to quantum information problems has also received significant interest recently, promising to directly probe the entanglement entropy as well as other properties. (2)
Quantum spin-chains are particular examples of exactly solvable or "quantum integrable" systems in 1+1 spacetime dimensions. Picture a ring of atoms (in order to have periodic boundary conditions) each of which possesses a quantum "degree of freedom", called a "spin", which can point in two directions, up or down. "Quantum" means that we allow for all complex linear superpositions of the different possible spin configurations of the ring, this set forms the physical state space. (Google)
Machine Learning for Quantum Matter.
This entry by a Vector Institute for Artificial Intelligence, Toronto mathematical physicist is a current example of the cross-integration of deep cerebral learning techniques with both classical physics and quantum domains.
Quantum matter, the research field studying material phases whose properties are intrinsically quantum mechanical, draws from areas as diverse as condensed matter physics, materials science, statistical mechanics, quantum information, quantum gravity, and large-scale numerical simulations. Here we review the recent adaptation of machine learning ideas for quantum matter studies, ranging from algorithms that recognize conventional and topological states in synthetic and experimental data, to quantum states in terms of neural networks and quantum many-body physics. (Abstract excerpt)
Animate Cosmos > Quantum Cosmology > quantum CS
Giannozzi, Paolo, et al.
Quantum ESPRESSO toward the Exascale.
Journal of Chemical Physics.
We cite this entry by fifteen European Union physicists as a current example of how this once intractable, basic domain is now readily being availed for all manner of material, computational, linguistic and practical advantages. This project noted below began in 2002, and is here reviewed “at the turn of the twenties.”
Quantum ESPRESSO is an open-source distribution of computer codes for quantum-mechanical materials modeling based on density-functional theory, pseudopotentials, and plane waves, and renowned for its performance on a wide range of hardware. In this paper, we present a review of the ongoing effort to port Quantum ESPRESSO onto heterogeneous architectures based on hardware accelerators, which will overcome the energy constraints that are currently slowing exascale computing. (Abstract)
Animate Cosmos > Quantum Cosmology > quantum CS
Quantum ESPRESSO Foundation: QEF is the home of this project for materials modeling at the nanoscale. We pledge ourselves to an open vision of science and software engineering. We foster the design, development, maintenance, and distribution of high-quality open-source software for the quantum simulation of matter, and we are committed to the dissemination of the art and science of scientific computing, by promoting training courses worldwide.
Kirchner, Stefan, et al.
Colloquium: Heavy-electron Quantum Criticality and Single-particle Spectroscopy.
Reviews of Modern Physics.
A seven person international effort from Zhejiang University, Vienna University, MPI Chemical Physics, University of Science and Technology of China, Los Alamos National Laboratory, and Rice University, TX provides deeply technical excursion through these newly open frontiers where strong signatures of critically poised states can again be found. For specific case, they appear in ytterbium, rhenium, silicon compositions and other complex chemicals, that is to say, innately throughout material nature.
Angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM) have become indispensable tools in the study of correlated quantum materials. Both probe complementary aspects of the single-particle excitation spectrum. ARPES and STM can study the electronic Green’s function, a central object of many-body theory. This review focuses on heavy-electron quantum criticality, especially the role of Kondo destruction. Particular emphasis is placed on the question of how to distinguish between the signatures of the initial onset of hybridization-gap formation, which characterizes the low-energy physics and, hence, the nature of quantum criticality. (Abstract excerpt)
Animate Cosmos > Quantum Cosmology > exouniverse
I. QUANTUM CRITICALITY: Quantum phase transitions occur at zero temperature and like their finite temperature counterparts, they can be either first order or continuous. In contrast to the finite temperature case where thermal fluctuations drive the transition, quantum fluctuations, encoded already at the Hamiltonian level, are responsible for the occurrence of a quantum phase transition. If the transition is continuous, characteristic, critical scaling ensues in its vicinity which reflects the singular correlations of the ground state wave function. (3)
Kartvelishvili, Guram, et al.
Self-Organized Critical Multiverse.
As nature’s phenomenal propensity to seek and reside at an optimum, complementary balance between certain particle/wave, conserve/create, me/We states gains notice everywhere, University of Pennsylvania astrophysicists including Justin Khoury scope out ways to detect its effect on this vast expanse. After citations of its wide presence (see quotes), a review of deep parameters from an inflationary start to now are seen to express such a nonlinear poise. In wider regard, as human beings are lately assaulted is so many ways, at the same while a worldwise intelligence discovers a multiUniVerse to EarthVerse of a bipartite, bigender code. As the website documents, this source code seems to be genetic in actual kind as a vital endowment. See also Dynamical Criticality and Higgs Metastability by JK at 1912.06706 and Search Optimization, Funnel Tomography, and Dynamical Criticality on the String Landscape by JK and Onkar Farrikar at 1907.07693. We post several quotes in support
Recently a dynamical selection mechanism for vacua based on search optimization was proposed in the context of false-vacuum eternal inflation on the landscape. The search algorithm is optimal in regions of the landscape where the dynamics are tuned at criticality, with de Sitter vacua having an average lifetime of order their Page time. The purpose of this paper is to shed light on the nature of the dynamical phase transition at the Page lifetime. Through a change of variables the master equation governing the comoving volume of de Sitter vacua is mapped to a stochastic equation for coupled overdamped stochastic oscillators . We show that the displacement fluctuations for the oscillators exhibit a 1/f power spectrum over a broad range of frequencies. A 1/f power spectrum is a hallmark of non-equilibrium systems at criticality. In analogy with neuronal avalanches in the brain, de Sitter vacua at criticality can be thought of as undergoing scale invariant volume fluctuation avalanches. (Abstract excerpt)
Animate Cosmos > Organic > Biology Physics
The discovery that string theory admits a vast landscape of metastable vacua, together with the mechanism of eternal inflation for dynamically populating these vacua, has led to a paradigm shift in our understanding of fundamental physics. It entails that statistical physics, possibly in conjunction with selection (anthropic) effects, played a role in determining the physical parameters of our universe. Like many other statistical systems, it is natural to expect that the multiverse can exhibit phase transitions. Indeed, it has been shown recently that certain regions of the landscape display non-equilibrium critical phenomena, in the sense that their vacuum dynamics are tuned at dynamical criticality. (1)
Non-equilibrium systems exhibiting 1/f fluctuation spectra are ubiquitous in nature. Examples include neuronal dynamics, heart beat variability, linguistics (Zipf’s law), economic time series (stock market prices), music and art. Thus, complex behavior appears intimately related to dynamical criticality. This has motivated the tantalizing idea of self-organizing criticality. While the subject is not without controversy, it is worth noting that our framework satisfies what are believed to be necessary conditions for self-organized criticality — our landscape region is out-of-equilibrium, open/dissipative, and slowly-driven. (3)
Complex self-organized systems poised at criticality are ubiquitous in the natural world. This has led to the conjecture that dynamical criticality is evolutionarily favored because it offers an ideal trade-off between robust response to external stimuli and flexibility of adaptation to a changing environment. In a forthcoming paper we will study another advantage of dynamical criticality, namely enhanced computational capabilities. Indeed, it has been argued that complex systems maximize their computational capabilities at the phase transition between stable and unstable dynamical behavior — the so-called “edge of chaos”. For instance, cellular automata with certain critical dynamical rules are capable of universal computation, exhibiting long-lived and complex transient structures. (9-10)
Xue, Chi, et al.
Scale-invariant Topology and Bursty Branching of Evolutionary Trees Emerge from Niche Construction.
Proceedings of the National Academy of Sciences.
University of Illinois genome biologists including Nigel Goldenfeld provide an exercise to show how, by way of statistical physics and network principles, that life’s circuitous, diverse, adaptive course can yet be found to have an intrinsic, self similar topology.
Phylogenetic trees describe both the evolutionary process and community diversity. Recent work has established that they exhibit scale-invariant topology, which quantifies the fact that their branching lies in between balanced binary trees and maximally unbalanced ones. Here, we present a simple, coarse-grained statistical model of niche construction coupled to speciation. Finite-size scaling analysis of the dynamics shows that the resultant phylogenetic tree topology is scale-invariant due to a singularity arising from large niche construction fluctuations that follow extinction events. The same model recapitulates the bursty pattern of diversification in time. (Abstract)
Animate Cosmos > Organic > Chemistry
McArdle, Sam, et al.
Quantum Computational Chemistry.
Review of Modern Physics.
Oxford University and University of Toronto materials scientists post a 51 page, 2020s tutorial as these three major scientific areas flow together and cross-inform each other. A further integration is also made with “classical” approaches, along with algorithmic methods and other skill sets so to compose a unified substantial synthesis.
A promising application of quantum computing is the solving of classically intractable chemistry problems. This may help explain phenomena such as high temperature superconductivity, solid-state physics, transition metal catalysis, and certain biochemical reactions. However, building a sufficient quantum computer for this purpose will be a scientific challenge. This review provides a comprehensive introduction with key methods to demonstrate how to map chemical problems onto a quantum computer, and to solve them. (Abstract excerpt)
Animate Cosmos > Organic > Universal
Campbell, John O. and Michael Price.
Universal Darwinism and the Origins of Order.
Georgiev, Georgi, et al, eds.
Evolution, Development and Complexity.
International: Springer, 2019.
In a chapter from a 2017 conference with the book title (search editor), a British Columbia independent researcher and a Brunel University evolutionary psychologist scope out a growing sense that life’s “variance – inheritance – selection” method is even in effect across temporal cosmic to cultural domains. By this view, this scheme becomes a computational, probabilistic iteration whence out of many contingent candidates an “optimum” result might eventually be achieved. The paper then introduces a novel quality that such a universe seems to favor and advance, namely an “accumulated knowledge repository.” As the Abstract and quote note, a five stage scale is cited whereof each phase contains more relative informational content.
In regard, this natural learning process serves to trace and track an oriented course from universe to us peoples, akin to J. A. Wheeler’s bit to it circuit. Although not mentioned, we Earthling interlocutors seem to be involved with its actual discovery, self-selection and literate cocreation. But an imagination of a greater phenomenal reality with an independent, genetic-like self-organization remains elusive to the authors and conference. The manifest knowledge resource, akin to Ken Richardson’s biogrammar (search), does not yet have a tangible identity. As it may at last ascend to our prodigious sapiensphere, maybe a global “geonome” appreciation would be apt.
In this chapter we describe a ‘universal Darwinism’ which proposes that the observable universe results from two types of processes: (1) disorder’s tendency to increase in isolated systems (second law of thermodynamics), and (2) Darwinian selection, which produces orderly entities that can withstand the second law. Darwinian processes generate complex order not just in the biological phase but in all five domains of nature as they exist in a nested hierarchy of cosmological, quantum, biological, neural, and cultural. Each qualifies as a distinct stage by being characterized by a relative ‘knowledge repository’, that is, a cumulative store of information about existence (e.g. a genome).
Animate Cosmos > Intelligence
Knowledge repositories are probabilistic models which make guesses about how to exist, which are then tested by the ‘embodied adapted system’ (e.g. phenotype). The repository then undergoes a Bayesian update, and thus becomes less ignorant and less entropic. These natural inferential systems evolve according to ‘variance – inheritance – selection’ Darwinian dynamics. For each new phase, its repository computationally transforms the substrate of the earlier domain (e.g., cultural repositories orchestrate the neural substrate), to generate new, innovative ways of overcoming the second law. We conclude that Darwinian theory, as an explanation for the origins of complex order in the universe, may be far more fundamental than is conventionally supposed. (Abstract)
We suggest that nature has utilized the selective Darwinian process to accumulate repositories of evolutionary knowledge within several domains of nature. We will discuss five types of autopoietic knowledge repositories, one in each domain of nature: (1) in the cosmological domain, this knowledge repository is represented by the laws and parameters of physics; (2) in the quantum domain, by quantum wave functions; (3) in the biological domain, by genomes (potentially acting in concert with epigenetic effects); (4) in the neural domain, by learned neural models; and (5) in the cultural domain, by cultural models. It is no accident that each natural domain possesses its own repository of accumulated knowledge, because the presence of such a knowledge repository is in fact our criterion for identifying each domain. (4)
Ecological Clues to the Nature of Consciousness.
The veteran theoretical ecologist (search) was at the University of Maryland Center for Environmental Sciences for many years where, among other projects, he served as a caretaker of Chesapeake Bay. In 1987 Bob and I had lunch with Ilya Prigogine at a conference. In this paper he illumes that Integrated Information and Global Workspace theories of cerebral function with regard to knowing awareness can have an affinity to similar environmental principles and vitalities.
Some dynamics associated with consciousness are shared by other complex macroscopic living systems. Autocatalysis, an active agency in ecosystems, imparts to them a centripetality, the ability to attract resources. It is likely that autocatalysis in the central nervous system gives rise to the phenomenon of selfhood. Similarly, a coherence domain, as constituted in terms of bi-level coordination in ecosystems, stands as an analogy to the simultaneous access the mind has to available information. The result is the feeling that one’s surroundings are present to the individual all at once. Similar research in other fields suggests empirical approaches to the study of consciousness in humans and other higher animals. (Abstract)
Animate Cosmos > Astrobiology
Cataldo, Franco, et al.
Petroleum, Coal and Other Organics in Space.
In a paper to appear in a special issue of Astrophysics and Space Science, Italian and French astrochemists discern and extend the pervasive presence of such organic, precursor biochemicals across a conducive spacescape. And we add such spontaneous formations of quite organic, fuel-like components well implies an innate, evolutionary fertility.
The petroleum and coal models of the unidentified infrared emissions (UIE), sometimes referred also as unidentified infrared bands (UIBs) has been reviewed mainly based on the work of the authors with the inclusion of unpublished results. It is shown that the petroleum and coal model of the UIE converges and merges quite well with the MAON (Mixed Aromatic Aliphatic Organic Nanoparticles) model of the UIE. It is shown that the thermal treatment of various substrates like PAHs, alkylated PAHs but also mixed aliphatic/olefinic substrates leads invariable to carbonaceous materials matching the infrared spectrum of anthracite coal or certain petroleum fractions. (Abstract excerpt)
Animate Cosmos > Astrobiology
The Quest for a Universal Theory of Life.
ambridge: Cambridge University Press,
The veteran University of Colorado philosopher of astrobiology surveys the past and present of unresolved efforts to explain ourselves and the life phenomenon of living systems across local and cosmic matter. With a nod to Aristotle and Darwin, is its essence self-organization or genetic reproduction, how can we ever define and know? But we add, it seems as long as (male) mindset rules that cannot imagine or allow any extant universe at all from which viability arises, no answer will be possible.
Animate Cosmos > exoearths
Gaudi, B. Scott, et al.
The Habitable Exoplanet Observatory Mission Concept Report.
We note this 500 page mission statement by some 200 astroscientists with a main base at Jet Propulsion Laboratory as a premier example into the 2030s of our collaborative Earthkind personsphere beginning to explore, quantify and spread forth in a revolutionary genesis universe.
Animate Cosmos > exoearths
Seyler, Lauren, et al.
Metabolomics as an Emerging Tool in the Search for Astrobiologically Relevant Biomarkers.
A seven member team from the Woods Hole Oceanographic Institution, Centro de Astrobiología, Madrid, Blue Marble Space Institute, Seattle, and Cal Tech including James Cleaves scope out how such an expansive –omics approach, properly integrated and applied, can well facilitate this grand new exoplanetary phase as Earthlings begin to search for near and far celestial neighbors.
It is now easy to sequence and recover microbial genomes from environmental samples. If transcriptional and translational functions can be assigned to these genomes, it should be possible to understand the molecular inputs and outputs of a microbial community. However, gene-based tools alone are presently insufficient to describe the full suite of chemical reactions and small molecules that compose a living cell. Metabolomic tools have developed quickly and now enable rapid detection and identification of small molecules within biological and environmental samples. These technologies will soon facilitate the detection of novel enzymatic activities, novel organisms, and potentially extraterrestrial life-forms. (Abstract)
Deutsch, Andreas amd Sabine Dormann.
Cellular Automaton Modeling of Biological Pattern Formation.
Technical University of Dresden complexity bioscientists provide a latest tutorial about nature’s essential propensity to iteratively organize her/his self into viable, universal scales of emergent genesis. Some chapter and section titles are On the Origin of Patterns, Ontogeny and Phylogeny, and Physical Analogues, Morphogenesis.
The book introduces pattern-forming principles in biology and the various mathematical modeling techniques used to analyze them. Cellular automaton models are discussed for different types of cellular processes and interactions, such as random movement, cell migration, adhesive cell interaction, alignment and cellular swarming, growth processes, pigment cell pattern formation, tumor growth, and Turing-type patterns. The final chapter discusses potentials and limits of the cellular automaton approach in modeling various biological applications, along with future research directions. (Publisher)
Zhang, Mengsen, et al.
Topological Portraits of Multiscale Coordination Dynamics.
Journal of Neuroscience Methods.
Florida Atlantic University and Stanford University researchers including Scott Kelso and Emmanuelle Tognoli (search) continue to finesse the presence and importance of nature’s scored choreography as it graces, informs and empowers our responsive cerebral performance. We note the mathematic approaches in bold as they find application to an increasing number of disparate many areas, which altogether imply a mindful ecosmic coordination.
Living systems exhibit complex yet organized behavior on multiple spatiotemporal scales. To investigate this phenomena, one needs a meaningful way to quantify the complex dynamics. This work shows how computational algebraic topology and dynamical systems theory can help meet this challenge. We propose, for example, a method to study dynamic topological information using persistent homology, which allows us to effectively construct a multiscale topological portrait of rhythmic coordination. The present work demonstrates how the analysis of multiscale coordination dynamics can benefit from topological methods, thereby paving the way for further systematic quantification of complex, high-dimensional dynamics in living systems. (Abstract excerpt)