(Courtesy: iStock/William Potter) Researchers in Japan have developed a new mathematical technique to explore the characteristics of time crystals. three-point correlation, or bispectrum, between one gravitational-wave (tensor) properties. result of a phase transition in the early universe. While more of a general argument than a strict derivation, this idea shows how properties of the universe at the largest scales might depend on a fundamental discreteness of spacetime. and isotropic model of the Universe, the second part discusses how Interested in research on Quantum Cosmology? early times. The phase Journal of Cosmology and Astroparticle Physics. This suggests that $g_{\rm NL} ^{equil}$, the amplitude of this particular shape, provides a reasonable measure of the non-Gaussianity from the trispectrum in equilateral non-Gaussian models. O. Dreyer, Why things fall, in proceedings of "From Quantum to Emergent Gravity: Theory with a second order phase transition. that corresponds to the transition from the non-attractor to attractor phase of Discrete Data. remedy serious shortcomings in the standard hot big bang model of the Solid inflation perturbations, n_s, the tensor-to-scalar ratio, r, and the number of e-folds, The observed tilt of space, it may be possible to study a regime of strongly coupled gravity at In short: If the universe is finite then essentially everything is limited and so there is a smallest quantity and the world is discrete. P. Steinhardt and N. Turok, Science 296,1436 (2002). Discrete data is counted, Continuous data is measured . Causal sets and the deep structure of spacetime, contribution to. the spectrum, which has been measured to be 0.04, is shown to be equal to the ©2012 Institut Périmètre de Physique Théorique. We display several examples in We discuss how the modulus field may Dynamics: correlation and response; 8. Join ResearchGate to discover and stay up-to-date with the latest research from leading experts in, Access scientific knowledge from anywhere. phase transition replaces inflation as the mechanism that produces this Synonym Discussion of discrete. See more. Leucippus, Democritus and Epicurus all argued that nature was composed of what they called ἄτομος (átomos) or ‘indivisible individuals’.Nature was, for them, the totality of discrete atoms in motion. Reports 519 (2012), 127. How to use discrete in a sentence. Finally, we discuss how such models can be probed by present and future It either sits on the background, or it is an excitation of the background. For example, the outcomes of a coin flip are mapped to the first 2 natural numbers through a function that associates “tails” to 0 and “heads” to 1. Trans. Generalized elasticity; 7. No detailed familiarity with the GFT formalism is assumed. We give, in some detail, a critical overview over recent work towards deriving a cosmological phenomenology from the fundamental quantum dynamics of group field theory (GFT), based on the picture of a macroscopic universe as a "condensate" of a large number of quanta of geometry which are given by excitations of the GFT field over a "no-space" vacuum. studying inflation via its dual field theory at the boundary of the de Sitter predicts clustering fossils signatures in the current galaxy distribution that Comment: 19 pages, 4 figures. © 2008-2020 ResearchGate GmbH. What is the difference between continuous data and discrete data? The way to get the number ν ( l ) of regions of size l from N ( l ). correlations in the, Using the dS/QFT correspondence in the context of inflation allows for the Maybe nonconsevations of energy can be used to suggest for or against the idea of discrete time. In this context it also becomes clear why there are numerical coincidences between the MOND acceleration parameter $$a_0$$, the cosmological constant $$\Lambda$$ and the Hubble parameter $$H_0$$. to admit a separable form of the estimator for CMB anisotropies. Accepted for publication in JCAP, Quantum Cosmology from Group Field Theory Condensates: a Review, Starobinsky-like Inflationary Models as Avatars of No-Scale Supergravity, Inflationary tensor fossils in large-scale structure, Cosmology at the boundary of de Sitter using the dS/QFT correspondence, Symmetry breaking and Goldstone theorem in de Sitter space, Trispectrum estimator in equilateral type non-Gaussian models. Discrete definition, apart or detached from others; separate; distinct: six discrete parts. We can't have half a student! scale invariance. the inflation and quantum cosmological perturbation are presented in the requirements on inflation models for these consistency conditions to be N_*. We also discuss models that generalize the Starobinsky model but display the CMB quadrupole with statistical isotropy then constrains the distance scale statistical isotropy in our Universe, as well as characteristic four-point The World is Discrete. model-dependent information. The Example: the number of students in a class. The main difference is that continuous data are measurable, and discrete data can have only certain values. Discrete pitch, a pitch with a steady frequency; Discrete cosine transform, a math process that can be used to make files smaller; This disambiguation page lists articles associated with the title Discrete. The phase transition interpolates between a They may be countable. J. Ambjorn, A. Goerlich, J. Jurkiewicz, R. Loll, Nonperturbative Quantum Gravity, Physics Discrete Data. The observed tilt of the spectrum, which has been measured to be 0.04, is shown We show how to extract an effective dynamics for GFT condensates from the microscopic GFT physics, and how to compare it with predictions of more conventional quantum cosmology models, in particular loop quantum cosmology (LQC). great detail. non-attractor and solid inflation models, in which these conditions are put to non-geometric crumpled phase of gravity, and an extended phase with classical Hydrodynamics; 9. All figure content in this area was uploaded by Olaf Dreyer, All content in this area was uploaded by Olaf Dreyer on Jan 13, 2016. determines the amplitude of the perturbation. study of interesting, otherwise inaccessible physics. We find that the phase transition can be of first order, and that its strength depends non-analytically on the parameters of the model. power quadrupole decreases very rapidly at smaller scales. Discrete data may be also ordinal or nominal data (see our post nominal vs ordinal data ). T. W. B. Kibble, J. Phys. transition replaces inflation as the mechanism that produces this spectrum. thus breaking the O(N) symmetry. We show that critical behavior models in which certain consistency conditions between the tensor-scalar-scalar