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Cosmological constant

Index Cosmological constant

In cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: Λ) is the value of the energy density of the vacuum of space. [1]

90 relations: Accelerating expansion of the universe, Affine connection, Albert Einstein, Alexander Friedmann, Alexander Vilenkin, Anthropic principle, Arthur Eddington, Big Rip, Brady Haran, California Institute of Technology, Chronology of the universe, Classical unified field theories, Cosmic microwave background, Dark energy, De Sitter invariant special relativity, Dimensional analysis, Edwin Hubble, Effective field theory, Einstein field equations, Einstein's constant, Energy density, Entropy, Epistemology, Equation of state (cosmology), Equilibrium point, Erwin Schrödinger, Fine-tuning, Gauge theory, General relativity, Gerard 't Hooft, Gravitational constant, Higgs boson, Higgs mechanism, History of variational principles in physics, Holographic principle, Inflation (cosmology), Inflaton, Inverse gambler's fallacy, Kitty Ferguson, Lambda, Lambda-CDM model, Lambdavacuum solution, Leonard Susskind, Light front quantization, Lisa Dyson, List of unsolved problems in physics, Local Group, Matthew Kleban, Metric tensor (general relativity), Milky Way, ..., Monthly Notices of the Royal Astronomical Society, Multiverse, Naturalness (physics), Occam's razor, Particle physics, Physical cosmology, Physics, Planck (spacecraft), Planck length, Pressure, Proportionality (mathematics), Prussian Academy of Sciences, Quantum chromodynamics, Quantum electrodynamics, Quantum field theory, Quantum fluctuation, Quintessence (physics), Redshift, Redshift survey, Ricci curvature, Scholarpedia, Scientific American, Sean M. Carroll, Second quantization, Shape of the universe, Spacetime, Speed of light, Standard Model, Static universe, Steven Weinberg, Stress–energy tensor, Supersymmetry, Type Ia supernova, University of Nottingham, Unruh effect, Vacuum, Vacuum energy, Vacuum state, Weak interaction, Yale University. Expand index (40 more) »

Accelerating expansion of the universe

The accelerating expansion of the universe is the observation that the universe appears to be expanding at an increasing rate, so that the velocity at which a distant galaxy is receding from the observer is continuously increasing with time.

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Affine connection

In the branch of mathematics called differential geometry, an affine connection is a geometric object on a smooth manifold which connects nearby tangent spaces, so it permits tangent vector fields to be differentiated as if they were functions on the manifold with values in a fixed vector space.

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Albert Einstein

Albert Einstein (14 March 1879 – 18 April 1955) was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics).

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Alexander Friedmann

Alexander Alexandrovich Friedmann (also spelled Friedman or Fridman; Алекса́ндр Алекса́ндрович Фри́дман) (June 16, 1888 – September 16, 1925) was a Russian and Soviet physicist and mathematician.

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Alexander Vilenkin

Alexander Vilenkin (Алекса́ндр Виле́нкин,Олександр Віленкін.; 13 May 1949, Kharkiv, Ukraine, Soviet Union) is Professor of Physics and Director of the Institute of Cosmology at Tufts University.

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Anthropic principle

The anthropic principle is a philosophical consideration that observations of the universe must be compatible with the conscious and sapient life that observes it.

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Arthur Eddington

Sir Arthur Stanley Eddington (28 December 1882 – 22 November 1944) was an English astronomer, physicist, and mathematician of the early 20th century who did his greatest work in astrophysics.

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Big Rip

In physical cosmology, the Big Rip is a hypothetical cosmological model concerning the ultimate fate of the universe, in which the matter of the universe, from stars and galaxies to atoms and subatomic particles, and even spacetime itself, is progressively torn apart by the expansion of the universe at a certain time in the future.

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Brady Haran

Brady John Haran (born 18 June 1976) is an Australian-born British independent filmmaker and video journalist who is known for his educational videos and documentary films produced for BBC News and his YouTube channels, the most notable being Periodic Videos and Numberphile.

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California Institute of Technology

The California Institute of Technology (abbreviated Caltech)The university itself only spells its short form as "Caltech"; other spellings such as.

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Chronology of the universe

The chronology of the universe describes the history and future of the universe according to Big Bang cosmology.

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Classical unified field theories

Since the 19th century, some physicists, notably Albert Einstein, have attempted to develop a single theoretical framework that can account for all the fundamental forces of nature – a unified field theory.

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Cosmic microwave background

The cosmic microwave background (CMB, CMBR) is electromagnetic radiation as a remnant from an early stage of the universe in Big Bang cosmology.

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Dark energy

In physical cosmology and astronomy, dark energy is an unknown form of energy which is hypothesized to permeate all of space, tending to accelerate the expansion of the universe.

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De Sitter invariant special relativity

In mathematical physics, de Sitter invariant special relativity is the speculative idea that the fundamental symmetry group of spacetime is the indefinite orthogonal group SO(4,1), that of de Sitter space.

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Dimensional analysis

In engineering and science, dimensional analysis is the analysis of the relationships between different physical quantities by identifying their base quantities (such as length, mass, time, and electric charge) and units of measure (such as miles vs. kilometers, or pounds vs. kilograms) and tracking these dimensions as calculations or comparisons are performed.

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Edwin Hubble

Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer.

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Effective field theory

In physics, an effective field theory is a type of approximation, or effective theory, for an underlying physical theory, such as a quantum field theory or a statistical mechanics model.

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Einstein field equations

The Einstein field equations (EFE; also known as Einstein's equations) comprise the set of 10 equations in Albert Einstein's general theory of relativity that describe the fundamental interaction of gravitation as a result of spacetime being curved by mass and energy.

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Einstein's constant

Einstein's constant or Einstein's gravitational constant, denoted (kappa), is the coupling constant appearing in the Einstein field equation which can be written: where is the Einstein tensor and is the stress–energy tensor.

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Energy density

Energy density is the amount of energy stored in a given system or region of space per unit volume.

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In statistical mechanics, entropy is an extensive property of a thermodynamic system.

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Epistemology is the branch of philosophy concerned with the theory of knowledge.

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Equation of state (cosmology)

In cosmology, the equation of state of a perfect fluid is characterized by a dimensionless number w, equal to the ratio of its pressure p to its energy density \rho: It is closely related to the thermodynamic equation of state and ideal gas law.

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Equilibrium point

In mathematics, specifically in differential equations, an equilibrium point is a constant solution to a differential equation.

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Erwin Schrödinger

Erwin Rudolf Josef Alexander Schrödinger (12 August 1887 – 4 January 1961), sometimes written as or, was a Nobel Prize-winning Austrian physicist who developed a number of fundamental results in the field of quantum theory, which formed the basis of wave mechanics: he formulated the wave equation (stationary and time-dependent Schrödinger equation) and revealed the identity of his development of the formalism and matrix mechanics.

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In theoretical physics, fine-tuning is the process in which parameters of a model must be adjusted very precisely in order to fit with certain observations.

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Gauge theory

In physics, a gauge theory is a type of field theory in which the Lagrangian is invariant under certain Lie groups of local transformations.

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General relativity

General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics.

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Gerard 't Hooft

Gerardus (Gerard) 't Hooft (born July 5, 1946) is a Dutch theoretical physicist and professor at Utrecht University, the Netherlands.

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Gravitational constant

The gravitational constant (also known as the "universal gravitational constant", the "Newtonian constant of gravitation", or the "Cavendish gravitational constant"), denoted by the letter, is an empirical physical constant involved in the calculation of gravitational effects in Sir Isaac Newton's law of universal gravitation and in Albert Einstein's general theory of relativity.

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Higgs boson

The Higgs boson is an elementary particle in the Standard Model of particle physics.

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Higgs mechanism

In the Standard Model of particle physics, the Higgs mechanism is essential to explain the generation mechanism of the property "mass" for gauge bosons.

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History of variational principles in physics

A variational principle in physics is an alternative method for determining the state or dynamics of a physical system, by identifying it as an extremum (minimum, maximum or saddle point) of a function or functional.

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Holographic principle

The holographic principle is a principle of string theories and a supposed property of quantum gravity that states that the description of a volume of space can be thought of as encoded on a lower-dimensional boundary to the region—preferably a light-like boundary like a gravitational horizon.

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Inflation (cosmology)

In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe.

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The inflaton field is a hypothetical scalar field that is theorized to drive cosmic inflation in the very early universe.

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Inverse gambler's fallacy

The inverse gambler's fallacy, named by philosopher Ian Hacking, is a formal fallacy of Bayesian inference which is an inverse of the better known gambler's fallacy.

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Kitty Ferguson

Kitty Gail Ferguson (née Vetter) (born December 16, 1941) is an American science writer, lecturer, and former professional musician.

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Lambda, Λ, λ (uppercase Λ, lowercase λ; λάμ(β)δα lám(b)da) is the 11th letter of the Greek alphabet.

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Lambda-CDM model

The ΛCDM (Lambda cold dark matter) or Lambda-CDM model is a parametrization of the Big Bang cosmological model in which the universe contains a cosmological constant, denoted by Lambda (Greek Λ), associated with dark energy, and cold dark matter (abbreviated CDM).

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Lambdavacuum solution

In general relativity, a lambdavacuum solution is an exact solution to the Einstein field equation in which the only term in the stress–energy tensor is a cosmological constant term.

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Leonard Susskind

Leonard Susskind (born 1940)his 60th birthday was celebrated with a special symposium at Stanford University.

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Light front quantization

The light-front quantization of quantum field theories provides a useful alternative to ordinary equal-time quantization.

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Lisa Dyson

Lisa Dyson (born 1974) is an American scientist and entrepreneur.

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List of unsolved problems in physics

Some of the major unsolved problems in physics are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result.

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Local Group

The Local Group is the galaxy group that includes the Milky Way.

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Matthew Kleban

Matthew Benjamin Kleban is an American theoretical physicist who works on string theory and theoretical cosmology.

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Metric tensor (general relativity)

In general relativity, the metric tensor (in this context often abbreviated to simply the metric) is the fundamental object of study.

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Milky Way

The Milky Way is the galaxy that contains our Solar System.

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Monthly Notices of the Royal Astronomical Society

Monthly Notices of the Royal Astronomical Society (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics.

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The multiverse (or meta-universe) is a hypothetical group of multiple separate universes including the universe in which humans live.

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Naturalness (physics)

In physics, naturalness is the property that the dimensionless ratios between free parameters or physical constants appearing in a physical theory should take values "of order 1" and that free parameters are not fine-tuned.

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Occam's razor

Occam's razor (also Ockham's razor or Ocham's razor; Latin: lex parsimoniae "law of parsimony") is the problem-solving principle that, the simplest explanation tends to be the right one.

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Particle physics

Particle physics (also high energy physics) is the branch of physics that studies the nature of the particles that constitute matter and radiation.

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Physical cosmology

Physical cosmology is the study of the largest-scale structures and dynamics of the Universe and is concerned with fundamental questions about its origin, structure, evolution, and ultimate fate.

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Physics (from knowledge of nature, from φύσις phýsis "nature") is the natural science that studies matterAt the start of The Feynman Lectures on Physics, Richard Feynman offers the atomic hypothesis as the single most prolific scientific concept: "If, in some cataclysm, all scientific knowledge were to be destroyed one sentence what statement would contain the most information in the fewest words? I believe it is that all things are made up of atoms – little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another..." and its motion and behavior through space and time and that studies the related entities of energy and force."Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves."Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. (...) You will come to see physics as a towering achievement of the human intellect in its quest to understand our world and ourselves."Physics is an experimental science. Physicists observe the phenomena of nature and try to find patterns that relate these phenomena.""Physics is the study of your world and the world and universe around you." Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over the last two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the scientific revolution in the 17th century, these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in academic disciplines such as mathematics and philosophy. Advances in physics often enable advances in new technologies. For example, advances in the understanding of electromagnetism and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.

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Planck (spacecraft)

Planck was a space observatory operated by the European Space Agency (ESA) from 2009 to 2013, which mapped the anisotropies of the cosmic microwave background (CMB) at microwave and infra-red frequencies, with high sensitivity and small angular resolution.

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Planck length

In physics, the Planck length, denoted, is a unit of length, equal to metres.

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Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.

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Proportionality (mathematics)

In mathematics, two variables are proportional if there is always a constant ratio between them.

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Prussian Academy of Sciences

The Royal Prussian Academy of Sciences (Königlich-Preußische Akademie der Wissenschaften) was an academy established in Berlin, Germany on 11 July 1700, four years after the Akademie der Künste, or "Arts Academy," to which "Berlin Academy" may also refer.

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Quantum chromodynamics

In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks and gluons, the fundamental particles that make up composite hadrons such as the proton, neutron and pion.

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Quantum electrodynamics

In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics.

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Quantum field theory

In theoretical physics, quantum field theory (QFT) is the theoretical framework for constructing quantum mechanical models of subatomic particles in particle physics and quasiparticles in condensed matter physics.

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Quantum fluctuation

In quantum physics, a quantum fluctuation (or vacuum state fluctuation or vacuum fluctuation) is the temporary change in the amount of energy in a point in space, as explained in Werner Heisenberg's uncertainty principle.

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Quintessence (physics)

In physics, quintessence is a hypothetical form of dark energy, more precisely a scalar field, postulated as an explanation of the observation of an accelerating rate of expansion of the universe.

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In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum.

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Redshift survey

In astronomy, a redshift survey is a survey of a section of the sky to measure the redshift of astronomical objects: usually galaxies, but sometimes other objects such as galaxy clusters or quasars.

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Ricci curvature

In differential geometry, the Ricci curvature tensor, named after Gregorio Ricci-Curbastro, represents the amount by which the volume of a small wedge of a geodesic ball in a curved Riemannian manifold deviates from that of the standard ball in Euclidean space.

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Scholarpedia is an English-language online wiki-based encyclopedia with features commonly associated with open-access online academic journals, which aims to have quality content.

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Scientific American

Scientific American (informally abbreviated SciAm) is an American popular science magazine.

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Sean M. Carroll

Sean Michael Carroll (born October 5, 1966) is a cosmologist and physics professor specializing in dark energy and general relativity.

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Second quantization

Second quantization, also referred to as occupation number representation, is a formalism used to describe and analyze quantum many-body systems.

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Shape of the universe

The shape of the universe is the local and global geometry of the universe.

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In physics, spacetime is any mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum.

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Speed of light

The speed of light in vacuum, commonly denoted, is a universal physical constant important in many areas of physics.

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Standard Model

The Standard Model of particle physics is the theory describing three of the four known fundamental forces (the electromagnetic, weak, and strong interactions, and not including the gravitational force) in the universe, as well as classifying all known elementary particles.

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Static universe

A static universe, also referred to as a "stationary" or "infinite" or "static infinite" universe, is a cosmological model in which the universe is both spatially infinite and temporally infinite, and space is neither expanding nor contracting.

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Steven Weinberg

Steven Weinberg (born May 3, 1933) is an American theoretical physicist and Nobel laureate in Physics for his contributions with Abdus Salam and Sheldon Glashow to the unification of the weak force and electromagnetic interaction between elementary particles.

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Stress–energy tensor

The stress–energy tensor (sometimes stress–energy–momentum tensor or energy–momentum tensor) is a tensor quantity in physics that describes the density and flux of energy and momentum in spacetime, generalizing the stress tensor of Newtonian physics.

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In particle physics, supersymmetry (SUSY) is a theory that proposes a relationship between two basic classes of elementary particles: bosons, which have an integer-valued spin, and fermions, which have a half-integer spin.

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Type Ia supernova

A type Ia supernova (read "type one-a") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf.

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University of Nottingham

The University of Nottingham is a public research university in Nottingham, United Kingdom.

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Unruh effect

The Unruh effect (or sometimes Fulling–Davies–Unruh effect) is the prediction that an accelerating observer will observe blackbody radiation where an inertial observer would observe none.

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Vacuum is space devoid of matter.

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Vacuum energy

Vacuum energy is an underlying background energy that exists in space throughout the entire Universe.

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Vacuum state

In quantum field theory, the quantum vacuum state (also called the quantum vacuum or vacuum state) is the quantum state with the lowest possible energy.

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Weak interaction

In particle physics, the weak interaction (the weak force or weak nuclear force) is the mechanism of interaction between sub-atomic particles that causes radioactive decay and thus plays an essential role in nuclear fission.

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Yale University

Yale University is an American private Ivy League research university in New Haven, Connecticut.

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Cosmic constant, Cosmological Constant, Cosmological constants, Cosmological term, Einstein's big blunder, Einstein's cosmological constant.


[1] https://en.wikipedia.org/wiki/Cosmological_constant

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