scholarly journals Nonlocal Quantum Effects in Cosmology

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Yurii V. Dumin
Keyword(s):  
Early Universe ◽  
Large Scale ◽  
Domain Walls ◽  
Early Stage ◽  
Topological Defects ◽  
Anomalous Behavior ◽  
Quantum Nonlocality ◽  
Ultracold Gases ◽  
Laboratory Studies ◽  
Microwave Background

Since it is commonly believed that the observed large-scale structure of the universe is an imprint of quantum fluctuations existing at the very early stage of its evolution, it is reasonable to pose the question: do the effects of quantum nonlocality, which are well established now by the laboratory studies, manifest themselves also in the early universe? We try to answer this question by utilizing the results of a few experiments, namely, with the superconducting multi-Josephson-junction loops and the ultracold gases in periodic potentials. Employing a close analogy between the above-mentioned setups and the simplest one-dimensional Friedmann-Robertson-Walker cosmological model, we show that the specific nonlocal correlations revealed in the laboratory studies might be of considerable importance also in treating the strongly nonequilibrium phase transitions of Higgs fields in the early universe. Particularly, they should substantially reduce the number of topological defects (e.g., domain walls) expected due to independent establishment of the new phases in the remote spatial regions. This gives us a hint on resolving a long-standing problem of the excessive concentration of topological defects, inconsistent with observational constraints. The same effect may be also relevant to the recent problem of the anomalous behavior of cosmic microwave background fluctuations at large angular scales.

scholarly journals Inflation, Microwave Background Anisotropy, and Open Universe Models

1996 ◽  
Vol 168 ◽  
pp. 321-327
Author(s):  
J.A. Frieman
Keyword(s):  
Early Universe ◽  
Large Scale ◽  
Large Scale Structure ◽  
Density Fluctuations ◽  
Inhomogeneous Distribution ◽  
Microwave Background ◽  
Inflationary Scenario ◽  
Open Universe ◽  
The Universe ◽  
Universe Models

The inflationary scenario for the very early universe has proven very attractive, because it can simultaneously solve a number of cosmological puzzles, such as the homogeneity of the Universe on scales exceeding the particle horizon at early times, the flatness or entropy problem, and the origin of density fluctuations for large-scale structure [1]. In this scenario, the observed Universe (roughly, the present Hubble volume) represents part of a homogeneous inflated region embedded in an inhomogeneous space-time. On scales beyond the size of this homogeneous patch, the initially inhomogeneous distribution of energy-momentum that existed prior to inflation is preserved, the scale of the inhomogeneities merely being stretched by the expansion.

DYNAMICS OF FERROMAGNETIC WALLS: GRAVITATIONAL PROPERTIES

2005 ◽  
Vol 14 (03n04) ◽  
pp. 521-541 ◽  
Author(s):  
L. CAMPANELLI ◽  
P. CEA ◽  
G. L. FOGLI ◽  
L. TEDESCO
Keyword(s):  
Domain Wall ◽  
Large Scale ◽  
Domain Walls ◽  
Background Radiation ◽  
Ideal Gas ◽  
Microwave Background ◽  
Electroweak Phase Transition ◽  
Microwave Background Radiation ◽  
The Universe ◽  
Negligible Contribution

We discuss a new mechanism which allows domain walls produced during the primordial electroweak phase transition. We show that the effective surface tension of these domain walls can be made vanishingly small due to a peculiar magnetic condensation induced by fermion zero modes localized on the wall. We find that in the perfect gas approximation the domain wall network behaves like a radiation gas. We consider the recent high-red shift supernova data and we find that the corresponding Hubble diagram is compatible with the presence in the Universe of an ideal gas of ferromagnetic domain walls. We show that our domain wall gas induces a completely negligible contribution to the large-scale anisotropy of the microwave background radiation.

EFFECTS OF PRIMORDIAL MAGNETIC FIELD ON EARLY UNIVERSE

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1695-1706 ◽  
Author(s):  
DAI G. YAMAZAKI ◽  
KIYOTOMO ICHIKI ◽  
KAJINO TOSHITAKA ◽  
GRANT J. MATHEWS
Keyword(s):  
Magnetic Field ◽  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Early Universe ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Microwave Background ◽  
Primordial Magnetic Field

The existence of a primordial magnetic field (PMF) would affect both the temperature and polarization anisotropies of the cosmic microwave background (CMB) and the formation of the large scale structure(LSS). It also provides a plausible explanation for the disparity between observations and theoretical fits to the CMB power spectrum and the LSS. Here we report on calculations of not only the numerical power spectrum of the PMF, but also the correlations between the PMF power spectrum and the primary curvature perturbations.

The Very Early Universe

1988 ◽  
Vol 20 (1) ◽  
pp. 656-658
Author(s):  
K. Sato
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Early Universe ◽  
Early Stage ◽  
Topological Defects ◽  
Evolution Of The Universe ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
The Universe

In recent years, the research on the very early universe has shown quite remarkable developments. As is well known, this development was brought about by the introduction of the Grand Unified Theories (GUTs) into cosmology. These theories have not only enabled us to trace the evolution of the Universe back to the very early stage at temperatures of 1016 GeV or higher, but also introduced various new aspects into cosmology, such as baryogenesis, phase transitions and topological defects (monopoles, etc.). In particular, inflation, which grew out of the study of GUT phase transition, is the most important and fascinating outcome.

The Cosmic Microwave Background

2020 ◽  
pp. 272-289
Author(s):  
Hui Chieh Teoh
Keyword(s):  
Cosmic Microwave Background ◽  
Early Universe ◽  
Large Scale ◽  
Big Bang ◽  
Space Missions ◽  
Expanding Universe ◽  
Microwave Background ◽  
The Big Bang ◽  
The Universe

The cosmic microwave background (CMB) holds many secrets of the origin and the evolution of our universe. This ancient radiation was created shortly after the Big Bang, when the expanding universe cooled and became transparent, sending an afterglow of light in all directions. It is a pattern frozen in place that dates back to 375,000 years after the birth of the universe. Numerous experiments and space missions have made increasingly higher resolution maps of the CMB radiation, with the aims to learn more about the conditions of our early universe and the origin of stars, galaxies, and the large-scale cosmic structures that populate our universe today.

scholarly journals Planck 2018 results

2020 ◽  
Vol 641 ◽  
pp. A1 ◽  
Author(s):  
◽  
N. Aghanim ◽  
Y. Akrami ◽  
F. Arroja ◽  
M. Ashdown ◽  
...  
Keyword(s):  
Early Universe ◽  
Large Scale ◽  
Power Spectra ◽  
Lessons Learned ◽  
Microwave Background ◽  
Λcdm Model ◽  
Astrophysical Objects ◽  
Standard Cosmological Model ◽  
Cosmic Microwave Background Data ◽  
Better Than

The European Space Agency’s Planck satellite, which was dedicated to studying the early Universe and its subsequent evolution, was launched on 14 May 2009. It scanned the microwave and submillimetre sky continuously between 12 August 2009 and 23 October 2013, producing deep, high-resolution, all-sky maps in nine frequency bands from 30 to 857 GHz. This paper presents the cosmological legacy of Planck, which currently provides our strongest constraints on the parameters of the standard cosmological model and some of the tightest limits available on deviations from that model. The 6-parameter ΛCDM model continues to provide an excellent fit to the cosmic microwave background data at high and low redshift, describing the cosmological information in over a billion map pixels with just six parameters. With 18 peaks in the temperature and polarization angular power spectra constrained well, Planck measures five of the six parameters to better than 1% (simultaneously), with the best-determined parameter (θ*) now known to 0.03%. We describe the multi-component sky as seen by Planck, the success of the ΛCDM model, and the connection to lower-redshift probes of structure formation. We also give a comprehensive summary of the major changes introduced in this 2018 release. The Planck data, alone and in combination with other probes, provide stringent constraints on our models of the early Universe and the large-scale structure within which all astrophysical objects form and evolve. We discuss some lessons learned from the Planck mission, and highlight areas ripe for further experimental advances.

Konkurrenz zwischen Stieleiche und Buche auf Lothar-Sturmflächen | Competition between pedunculate oak and European beech on Lothar windthrow areas

2009 ◽  
Vol 160 (5) ◽  
pp. 114-123 ◽  
Author(s):  
Daniel Otto ◽  
Sven Wagner ◽  
Peter Brang
Keyword(s):  
Large Scale ◽  
Early Stage ◽  
Tree Height ◽  
European Beech ◽  
Threshold Value ◽  
Test Methods ◽  
Permanent Plots ◽  
Pedunculate Oak ◽  
Competitive Pressure ◽  
Competition Index

The competitive pressure of naturally regenerated European beech (Fagus sylvatica) saplings on planted pedunculate oak (Quercus robur) was investigated on two 1.8 ha permanent plots near Habsburg and Murten (Switzerland). The plots were established with the aim to test methods of artificial oak regeneration after large-scale windthrow. On both plots, 80 oaks exposed to varying levels of competitive pressure from at most 10 neighbouring beech trees were selected. The height of each oak as well as stem and branch diameters were measured. The competitive pressure was assessed using Schütz's competition index, which is based on relative tree height, crown overlap and distance from competing neighbours. Oak trees growing without or with only slight competition from beech were equally tall, while oaks exposed to moderate to strong competition were smaller. A threshold value for the competition index was found above which oak height decreased strongly. The stem and branch diameters of the oaks started to decrease even if the competition from beech was slight, and decreased much further with more competition. The oak stems started to become more slender even with only slight competition from beech. On the moderately acid beech sites studied here, beech grow taller faster than oak. Thus where beech is competing with oak and the aim is to maintain the oak, competitive pressure on the oak must be reduced at an early stage. The degree of the intervention should, however, take the individual competitive interaction into account, with more intervention if the competition is strong.

scholarly journals Favorable Effects of GLP-1 Receptor Agonist against Pancreatic β-Cell Glucose Toxicity and the Development of Arteriosclerosis: “The Earlier, the Better” in Therapy with Incretin-Based Medicine

2021 ◽  
Vol 22 (15) ◽  
pp. 7917
Author(s):  
Hideaki Kaneto ◽  
Tomohiko Kimura ◽  
Masashi Shimoda ◽  
Atsushi Obata ◽  
Junpei Sanada ◽  
...  
Keyword(s):  
Large Scale ◽  
Cell Function ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Insulin Biosynthesis ◽  
Protective Effects ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Toxicity

Fundamental pancreatic β-cell function is to produce and secrete insulin in response to blood glucose levels. However, when β-cells are chronically exposed to hyperglycemia in type 2 diabetes mellitus (T2DM), insulin biosynthesis and secretion are decreased together with reduced expression of insulin transcription factors. Glucagon-like peptide-1 (GLP-1) plays a crucial role in pancreatic β-cells; GLP-1 binds to the GLP-1 receptor (GLP-1R) in the β-cell membrane and thereby enhances insulin secretion, suppresses apoptotic cell death and increase proliferation of β-cells. However, GLP-1R expression in β-cells is reduced under diabetic conditions and thus the GLP-1R activator (GLP-1RA) shows more favorable effects on β-cells at an early stage of T2DM compared to an advanced stage. On the other hand, it has been drawing much attention to the idea that GLP-1 signaling is important in arterial cells; GLP-1 increases nitric oxide, which leads to facilitation of vascular relaxation and suppression of arteriosclerosis. However, GLP-1R expression in arterial cells is also reduced under diabetic conditions and thus GLP-1RA shows more protective effects on arteriosclerosis at an early stage of T2DM. Furthermore, it has been reported recently that administration of GLP-1RA leads to the reduction of cardiovascular events in various large-scale clinical trials. Therefore, we think that it would be better to start GLP-1RA at an early stage of T2DM for the prevention of arteriosclerosis and protection of β-cells against glucose toxicity in routine medical care.

scholarly journals Understanding the Processes Causing the Early Intensification of Hurricane Dorian through an Ensemble of the Hurricane Analysis and Forecast System (HAFS)

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Andrew Hazelton ◽  
Ghassan J. Alaka ◽  
Levi Cowan ◽  
Michael Fischer ◽  
Sundararaman Gopalakrishnan
Keyword(s):  
Tropical Cyclone ◽  
Large Scale ◽  
Early Stage ◽  
Early Period ◽  
Storm Track ◽  
Key Factors ◽  
Complex Interplay ◽  
Forecast System ◽  
Model Initialization

The early stages of a tropical cyclone can be a challenge to forecast, as a storm consolidates and begins to grow based on the local and environmental conditions. A high-resolution ensemble of the Hurricane Analysis and Forecast System (HAFS) is used to study the early intensification of Hurricane Dorian, a catastrophic 2019 storm in which the early period proved challenging for forecasters. There was a clear connection in the ensemble between early storm track and intensity: stronger members moved more northeast initially, although this result did not have much impact on the long-term track. The ensemble results show several key factors determining the early evolution of Dorian. Large-scale divergence northeast of the tropical cyclone (TC) appeared to favor intensification, and this structure was present at model initialization. There was also greater moisture northeast of the TC for stronger members at initialization, favoring more intensification and downshear development of the circulation as these members evolved. This study highlights the complex interplay between synoptic and storm scale processes in the development and intensification of early-stage tropical cyclones.

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