Astrophysics stubs

In the context of Wikipedia, an "Astrophysics stub" refers to a very short or incomplete article related to astrophysics that is not sufficiently detailed to provide a comprehensive overview of the topic. Stubs are often marked with a specific template that indicates to editors and readers that the article needs expansion and additional information. The purpose of stubs is to encourage contributions from other users who might have expertise or additional resources to improve the article.

In the context of Wikipedia, a "stub" is a very short article or entry that provides minimal information on a topic. Physical cosmology stubs refer specifically to articles about physical cosmology that are not fully developed. These articles may provide some basic information about concepts, theories, or phenomena related to physical cosmology but lack depth, detail, or extensive references.

The Affleck–Dine mechanism is a theoretical framework in particle physics and cosmology that explains how certain types of baryogenesis (the process that generates an asymmetry between baryons and antibaryons in the universe) can occur in the context of supersymmetry. Proposed by Ian Affleck and Michael Dine in the late 1980s, this mechanism is notable for providing a possible way to create a baryon asymmetry during the early universe.

"Big Brake" usually refers to a performance upgrade for vehicles, specifically concerning the braking system. It involves installing larger brake components—such as rotors, calipers, and pads—in order to enhance stopping power, heat dissipation, and overall braking performance. The main benefits of a big brake system include: 1. **Increased Stopping Power**: Larger rotors provide more surface area for the brake pads to grip, which can lead to shorter stopping distances.

CMBFAST is a computational code used for calculating the anisotropies in the cosmic microwave background (CMB) radiation. Developed by Uros Seljak and Matias Zaldarriaga in the late 1990s, CMBFAST solves the Boltzmann equations that describe the evolution of the CMB's temperature fluctuations and polarization, among other properties related to the early Universe.

ChaNGa (Charon N-body GrAvity) is a computer code designed for simulating gravitational N-body systems. It is particularly used for astrophysical simulations that involve the dynamics of stars, galaxies, and dark matter in the universe. ChaNGa employs a tree code algorithm for calculating gravitational forces, which allows it to efficiently handle large numbers of particles while maintaining high accuracy.

Chaplygin gas is a theoretical model in cosmology that describes a type of fluid characterized by a specific equation of state. It is named after the Russian mathematician Sergey Chaplygin, who introduced the concept in the early 20th century.

"Coma filament" typically refers to a specific structure in astrophysics related to the distribution of dark matter and galaxies within the large-scale structure of the universe. In this context, "comas" are clusters of galaxies that are connected by filaments of dark matter and gas, forming a "cosmic web" structure. These filaments represent the densest areas where matter is concentrated, and they play a crucial role in the formation and evolution of galaxies.

Cosmic crystallography is a field of study that combines concepts from crystallography—the science of studying the arrangement of atoms within crystalline solids—with cosmology, the branch of astronomy that deals with the origins and development of the universe. While the term may not be widely recognized in traditional scientific literature, it can refer to the examination of the crystalline structures that can exist in various cosmic environments, such as in stars, meteoroids, comets, and on planetary bodies.

The DEEP2 Redshift Survey is an astronomical survey aimed at studying the formation and evolution of galaxies in the universe. Conducted using the Keck Observatory in Hawaii, this survey focuses on obtaining redshifts for a large sample of galaxies to provide insights into their distances, motions, and properties across a significant portion of cosmic time.

The term "Dark Siren" can refer to a variety of concepts depending on the context. Here are a few possible interpretations: 1. **Mythological Reference**: In mythology, sirens are often depicted as alluring creatures that lure sailors to their doom with enchanting music and voices. A "dark siren" might imply a particularly malevolent or sinister version of this archetype, perhaps associated with themes of seduction and danger.

Dipole anisotropy typically refers to a directional dependence in a physical quantity, often observed in the context of cosmic phenomena or fields. In cosmology, for example, dipole anisotropy is often discussed in relation to the Cosmic Microwave Background (CMB) radiation. In this context, the CMB is the afterglow of the Big Bang, and while it is generally uniform, it does exhibit slight variations in temperature that can be analyzed.

A domain wall refers to a boundary between two regions, or "domains," in a material where the direction of magnetization, polarization, or some other order parameter changes. Domain walls are particularly significant in the fields of magnetism and ferroelectricity. ### In Ferromagnetic Materials: In ferromagnetic materials, magnetization vectors can point in different directions within distinct regions (domains).

In the context of astronomy, "dropout" typically refers to a type of galaxy that is not observed in certain wavelengths of light, particularly in the ultraviolet or optical bands, but is detected in longer wavelengths such as infrared. This phenomenon is often indicative of high-redshift galaxies, which are many billions of light-years away and play a crucial role in our understanding of the early universe. The term "dropout" is most commonly used in the context of surveys designed to find and study such galaxies.

The Ehlers–Geren–Sachs theorem is a result in general relativity that addresses the behavior of gravitational fields and the geometry of spacetime around certain kinds of distributions of matter. Specifically, it relates to the nature of gravitational waves and the properties of the spacetime in the presence of gravitational radiation. The theorem states that under suitable conditions, if a gravitational wave is present in a vacuum region of spacetime, then the geometry of the spacetime exhibits specific features.

A "Fermi ball" is a concept that arises in quantum mechanics and particle physics, specifically in the context of describing the distribution of particles in momentum space. The term is often used in discussions related to Fermi-Dirac statistics, which govern the behavior of fermions — particles such as electrons. In a Fermi gas, the distribution of particles at absolute zero temperature can be depicted as a ball in momentum space, where the radius of the ball corresponds to the Fermi momentum.

The Fischler-Susskind mechanism, proposed by Steven Fischler and Leonard Susskind in the early 1980s, is a theoretical framework within string theory that aims to address the problem of generating mass for gauge bosons, which are the force carriers of fundamental interactions, particularly in the context of particle physics.

Freeman law is primarily associated with a legal doctrine concerning the treatment of prophetic or factual statements made in the context of contractual obligations and the expectations that arise from them. More specifically, it pertains to the principle of "freeman" or "freeman-ship," often interpreted in the context of business and commercial law.

The term "Gold universe" can have different meanings depending on the context in which it is used. It generally refers to concepts related to gold as a commodity or investment, particularly in finance or economics. Here are a few potential interpretations: 1. **Investment Universe**: In investment contexts, the "gold universe" could refer to the range of available gold-related investment options. This can include physical gold, gold mining stocks, gold ETFs (Exchange-Traded Funds), and derivatives based on gold prices.

The gravitational memory effect, also known as the "gravitational memory" or "memory effect in gravity," refers to a phenomenon predicted by general relativity in the context of gravitational waves. It describes how the passage of a gravitational wave can leave a permanent change in the separation between two freely falling test masses after the wave has passed. When a gravitational wave propagates through space, it creates a ripple in spacetime, causing spacetime to stretch and compress.

Himiko is a Lyman-alpha blob, which is a type of astronomical object characterized by an extended region of hydrogen gas that emits Lyman-alpha radiation. These blobs are typically found at high redshifts, indicating that they are situated at significant distances from Earth and are observed as they were in the early universe. Himiko itself is noteworthy because it is one of the largest and most luminous Lyman-alpha blobs discovered to date.

The Hubble Legacy Field is a significant astronomical image created using data from the Hubble Space Telescope. It represents a compilation of observations from a wide range of wavelengths, focusing on a small patch of the sky in the constellation Fornax. This field contains the deepest and most detailed view of the universe ever captured by the Hubble telescope.

The Lynx–Ursa Major Filament is a large-scale structure in the universe that is part of the cosmic web, consisting of a series of galaxy clusters and groups interconnected by vast amounts of dark matter and gas. This filament stretches through the constellations Lynx and Ursa Major and is notable for its substantial density of galaxies, making it a significant feature for astronomers studying the large scale structure of the universe.

Non-Gaussianity refers to the deviation of a probability distribution from a Gaussian (normal) distribution. In a Gaussian distribution, data is symmetrically distributed around the mean, with most values clustering around the center and fewer values appearing as you move farther from the mean. The characteristics of a Gaussian distribution can be completely described by its mean and variance. When data exhibits non-Gaussianity, it means that its distribution does not follow this normal pattern.

The Ostriker–Peebles criterion is a criterion in astrophysics used to evaluate the stability of spherical systems of matter under gravitational collapse, particularly in the context of galaxy formation and the large-scale structure of the universe. It is named after the astronomers J. P. Ostriker and P. J. E. Peebles. The criterion assesses whether a system, such as a cloud of gas or a cluster of galaxies, is stable against perturbations.

Particle physics in cosmology is the study of the fundamental particles and forces that govern the universe at its most basic level, particularly in the context of its large-scale structure, evolution, and fundamental properties. It combines principles from both particle physics and cosmology to explore how elementary particles, such as quarks, leptons, and gauge bosons, contribute to the makeup of the universe and its dynamic behavior.

The "Past Hypothesis" is a concept from the philosophy of science, particularly in the context of thermodynamics and statistical mechanics. It proposes that the initial conditions of the universe were such that it began in a low-entropy state, which is crucial for explaining the arrow of time and the emergence of macroscopic phenomena. In simpler terms, the Past Hypothesis suggests that the universe started in a highly ordered state, with minimal disorder (or low entropy) at the Big Bang.

The Perseus–Pegasus Filament is a large-scale structure in the universe, specifically a cosmic filament, that is part of the larger cosmic web. It is a region in space where galaxies are distributed along elongated structures, often forming a network of interconnected strands, or filaments, that are separated by voids. This filament lies in the direction of the constellations Perseus and Pegasus and is known for its high density of galaxies.

Phantom energy is a theoretical concept in cosmology associated with the accelerated expansion of the universe. It is a type of dark energy with an equation of state parameter \( w \) that is less than -1. This means that the pressure exerted by phantom energy is more negative than its energy density. In standard cosmological models, dark energy typically has an equation of state parameter \( w \) around -1, corresponding to the cosmological constant.

The Primordial Isocurvature Baryon model is a theoretical framework in cosmology that deals with the various types of fluctuations present in the early universe. To understand this model, it's essential to break down a few key concepts. ### Key Concepts: 1. **Cosmic Microwave Background (CMB)**: This is the afterglow radiation from the Big Bang, which provides a snapshot of the early universe.

The Quintom scenario is a concept that originates from the field of cosmology and theoretical physics, particularly in relation to dark energy and the acceleration of the universe's expansion. It describes a hypothetical model for the universe's evolution involving different phases of cosmic expansion. In the Quintom scenario, the universe is thought to transition between different states of dark energy.

A radio halo is a type of diffuse emission found in some galaxy clusters, which appears as a large, extended region of radio waves emitting cosmic rays and relativistic electrons. Radio halos are typically associated with the presence of turbulent magnetic fields and are thought to be a result of the interactions within the intracluster medium (ICM) during cluster mergers. These structures are observed at wavelengths of several centimeters to several meters and are often studied using radio telescopes.

The term "Shapley Attractor" is often associated with concepts in game theory and economics, particularly in the context of cooperative games and the allocation of resources. However, the phrase may also appear in other scientific fields such as dynamical systems and ecology. In the context of game theory, the Shapley value, developed by Lloyd Shapley, is a solution concept that assigns a value to each player based on their contributions to the total payoff.

In cosmology, "texture" refers to a theoretical model of the universe that describes certain types of topological defects, particularly in the context of scalar fields in the early universe. These textures are solutions to field equations that arise in various field theories, particularly those involving spontaneous symmetry breaking. Textures are characterized by regions of space where scalar fields take on different vacuum states, leading to the formation of localized structures in the cosmic medium.

The Giant Arc refers to a massive cosmic structure discovered in recent astronomical surveys. It is characterized as a large-scale arrangement of galaxies and galaxy clusters that spans a significant portion of the observable universe. The Giant Arc stretches for about 3.3 billion light-years and is notable for containing a relatively low density of matter compared to other regions.

The Ursa Major Filament is a vast cosmic structure in the universe consisting of a group of galaxies and galaxy clusters that are connected by gravitational forces and dark matter. This filament is part of the larger cosmic web, which is the large-scale structure of the universe. The filament gets its name from its location in the sky near the Ursa Major constellation. Cosmic filaments are critically important for cosmology, as they provide insights into the formation of galaxies and the distribution of matter in the universe.

As of my last update in October 2021, Vorton is not a widely recognized term in any particular field. However, it might refer to a specific company, technology, or product that emerged or gained prominence after that date.

Weyl's postulate, formulated by Hermann Weyl in 1921, is a hypothesis relating to the large-scale structure of the universe. According to Weyl's postulate, at a sufficiently large scale, the universe is homogeneous and isotropic; that is, it appears the same in all directions (isotropic) and has a uniform distribution of matter (homogeneous) when averaged over large enough volumes.

G-Cloud, short for Government Cloud, is a UK government initiative designed to facilitate the procurement of cloud computing services for public sector organizations. Launched in 2012, G-Cloud aims to make it easier, quicker, and more cost-effective for government entities to acquire cloud-based services and technology. The G-Cloud framework includes a digital marketplace where suppliers can offer their cloud services—such as hosting, software, and storage solutions—directly to government buyers.

Alpha Centauri is a star system located approximately 4.37 light-years from Earth, making it the closest star system to our solar system. It consists of three stars: Alpha Centauri A, Alpha Centauri B, and Proxima Centauri.

Alpha Centauri is often depicted in science fiction as a neighboring star system to our own, primarily due to its proximity—about 4.37 light years away from Earth. This makes it an attractive setting for various speculative stories, as it is one of the closest systems that could potentially harbor planets and life.

The 2069 Alpha Centauri mission refers to a hypothetical future space exploration project aimed at sending a spacecraft to the Alpha Centauri star system, which is the closest known star system to Earth, located about 4.37 light-years away. The timeline suggests that this mission would take place around the year 2069, marking the 50th anniversary of various initiatives to explore nearby star systems.

AIMStar is a term that could refer to different things depending on the context, but as of my last knowledge update in October 2023, it is primarily associated with AIMStar International, a company focused on technology and educational solutions. AIMStar may also refer to various products, services, or initiatives in different sectors like software, education, or online platforms.

Alpha Centauri Bb is an exoplanet that orbits the star Alpha Centauri B, one of the three stars in the Alpha Centauri star system, which is located approximately 4.37 light-years away from Earth. It is notable for being one of the closest known exoplanets to our solar system. Discovered in 2012, Alpha Centauri Bb is classified as a "super-Earth," a type of planet that is larger than Earth but smaller than Neptune.

Breakthrough Starshot is an initiative launched in 2016 aimed at developing a new method for interstellar travel. The primary goal of the project is to send small, lightweight spacecraft called "StarChips" to the Alpha Centauri star system, which is about 4.37 light-years away from Earth. The program was founded by a group of prominent scientists and entrepreneurs, including physicist Stephen Hawking, entrepreneur Yuri Milner, and cosmologist Neil deGrasse Tyson, among others.

"Candidate 1" could refer to various things depending on the context. It could be a name used in political discussions, job applications, scientific studies, or any selection process where individuals are being evaluated.

Project Longshot is a theoretical concept for a spacecraft designed to explore the Alpha Centauri star system, which is the closest known star system to Earth, located about 4.37 light-years away. The project was initially conceived by NASA in collaboration with the US Naval Academy in the 1980s. It aimed to develop a spacecraft capable of making the journey to Alpha Centauri within a human lifetime.

Proxima Centauri is a red dwarf star located in the Alpha Centauri star system, which is the closest star system to Earth, situated about 4.24 light-years away. Proxima Centauri is the smallest and faintest of the three stars in this system, the other two being Alpha Centauri A and Alpha Centauri B, which are more similar to our Sun.

Starlight is a proposed interstellar probe concept that aims to explore beyond our solar system, targeting the nearest star systems. While specific details about the mission may evolve, the primary goal of Starlight is to advance our understanding of nearby planetary systems, which could potentially harbor extraterrestrial life. Starlight belongs to a broader category of interstellar mission concepts that have emerged in recent years, driven by technological advancements and a greater interest in the search for habitable environments beyond Earth.