main tags laws scientists sections authors graph theory
Popular

Sachs–Wolfe effecteffect

# tag · @ author · ! scientist
62 Related articles
In 1967, Rainer K. Sachs and Arthur M. Wolfe showed that gravitational redshift explains the main anisotropies of the CMB. Before that, cosmologists puzzled over the origin of the microwave sky's patchiness. The idea is simple: a photon leaving a gravitational well loses energy, while one falling into a well gains it. But at the time of CMB emission, the wells were shallow, and photons escaped almost freely, slightly cooled. The total temperature change is proportional to the difference in gravitational potential at the emission point and on Earth. Since Earth is in a very weak field, the main contribution comes from the potential at the last scattering surface. It's like launching balls from different depths of a pool: the deeper, the slower the ball emerges to the surface.

How it works

The effect contributes the main difference in temperature between points on the CMB map for angles larger than a couple of degrees. It is used to reconstruct the distribution of dark matter at the time of recombination.

💡 Thanks to the Sachs–Wolfe effect, astronomers can 'weigh' the most distant galaxy clusters without even seeing them: from the temperature of spots, they estimate the gravitational potential at recombination.
\Delta T / T = -\Phi / (3c^2)
ΔT/T — relative CMB temperature fluctuation; Φ — gravitational potential (positive for regions of compression), measured in m²/s²; c ≈ 3×10⁸ m/s — speed of light
Links in the knowledge graph 1
Discovered by
Rainer Sachs
Related concepts
baryon acoustic oscillationscosmic microwave backgroundgravityredshiftReionization
Related laws
Doppler effectHubble's lawgravitational lensing

Related articles

The Conductor with a False Note: Why Quintessence Couldn't Save Inflation

The quintessential inflation model based on α-attractors describes inflation and modern dark energy as different roles of a single scalar field. Its key prediction is a kination stage, which amplifies high-frequency gravitational waves and leaves an imprint on the cosmic microwave background and pri
arXiv:2605.00735v1 · 2026-05-01

Gravitational Duet: How Entangled Masses Listen to the Whisper of Other Dimensions

Extra dimensions have long evaded detection due to electromagnetic noise. The protocol of quantum-induced entanglement of masses turns two microscopic bodies in superposition into gravitational tuning forks, accumulating a phase shift exquisitely sensitive to deviations from Newton's law. Analysis o
arXiv:2605.00749v1 · 2026-05-01

Lightning over the Horizon: The Collapse of Semiclassical Gravity in Black Hole Evaporation

The information paradox of black holes requires accounting for quantum effects in strong gravity. The semiclassical approach, proposed by Stephen Hawking, assumes that quantum fields on a fixed curved background lead to radiation and mass loss, but the backreaction of radiation on geometry is a crit
arXiv:2605.00780v1 · 2026-05-01

Cosmic Gong: How a Black Hole Rings a Wormhole

Scientists have calculated the gravitational radiation from a stellar-mass black hole radially falling into a thin-shell wormhole. The signal resembles rhythmic beats: a burst as the black hole approaches the throat from our side, and a deep silence as it plunges into another universe. Calculations
arXiv:2605.01216v1 · 2026-05-02

Improvisation beneath the horizon: quantum bounce turns a black hole into a white hole

The event horizon of a black hole conceals not a point of infinite curvature, but a zone of quantum transformation, where time itself changes roles. New research in quantum gravity shows: the singularity vanishes thanks to relational dynamics — one of the metric variables serves as a clock, and the
arXiv:2605.01576v1 · 2026-05-02

The Black Hole's Spin Signature: Polarization Ripples on Its Shadow

New research reveals a subtle mechanism: polarization doesn't just illuminate a black hole's shadow — it deforms it. The effect, predicted for rotating holes, is vanishingly small but fundamental: polarimetry transforms from a passive spectator into an active probe of extreme gravity. In a static sc
arXiv:2605.02136v2 · 2026-05-04

Ocean of Currents: Why the Universe's Acceleration Varies with Direction

What if the cosmic ocean expands unevenly? Using 1701 supernovae from Pantheon+, astrophysicists checked this and found a disturbing ripple — a dipole anisotropy in q0. But once they accounted for galaxies' peculiar velocities, the illusion almost dissolved. It's an artifact of our own drift, not ex
arXiv:2605.03004v1 · 2026-05-04

Cosmic Tuning Fork: Earth and Moon Resonate with Gravitational Waves

A novel laser ranging technique aims to fill the microhertz gap in gravitational-wave astronomy. By exploiting resonant enhancement at the second harmonic of the Moon’s orbit and phase measurements precise to 80 micrometers, a five-year campaign could reach a sensitivity of Ω_gw ≈ 5×10⁻⁹ — enough to
arXiv:2605.04110v1 · 2026-05-04

Breath of the Abyss: How a Black Hole's Horizon Pulsates to the Rhythm of Accretion

Analog gravity doesn’t freeze in weak perturbations. When gas roars onto a black hole, it gives birth to a living acoustic spacetime—a horizon that oscillates and shifts. Using an equation of state for ultrahot plasma with a variable adiabatic index, the authors showed that the horizon radius dances
arXiv:2605.04158v2 · 2026-05-05

Alchemy of the Void: Nonlocal Magic of Particle Birth

Schwinger pair production in gauge fields reveals the unexpected depth of the vacuum: instead of simple entanglement, nonlocal magic arises—correlations that cannot be described without a full-fledged quantum computer. Holographic duality links this magic to the geometry of strings and black holes,
arXiv:2605.04210v1 · 2026-05-05

Gravitational Shooting Gallery: Sighting in on Black Holes

For the first time, nonlinear simulations of black hole flybys in modified gravity have been performed — test shots on the cosmic range. Comparing the scattering angles with analytics hit nearly the bullseye: the difference stayed within one degree. This paves the way for rapid gravitational wave te
arXiv:2605.04224v1 · 2026-05-05

Cosmic Hourglass: The Flickering Shadow of a Wormhole

Numerical simulations revealed how plasma gets stuck in the throat of a rotating wormhole, painting a thin luminous rim on its shadow and making it flicker with a period set by mass and spin. These signatures, observable by the Event Horizon Telescope at 230 GHz, turn active galactic nuclei into nat
arXiv:2605.04631v1 · 2026-05-06

Gravitational Shadows: How Mass Splits Reality

Matter interferometry creates a Schrödinger's cat for macroscopic masses, opening the path to quantum gravity. A mass in superposition generates two clouds of coherent gravitons — gravitational shadows. Their contrast drops exponentially with increasing mass, signaling the growing entanglement betwe
arXiv:2605.05153v1 · 2026-05-06

The Cosmic Loom: The Puzzle of Missing Antimatter and Inflation

A new leptogenesis scenario shows: heavy Majorana neutrinos, born from the vacuum by post-inflation expansion, gave rise to the entire baryon asymmetry. Their mass almost mystically matches the inflation scale — and it's no accident: the amplitude of primordial gravitational waves becomes a direct e
arXiv:2605.05304v1 · 2026-05-06

Torus Universe: A Quantum Jackpot for the Big Bang

Quantum cosmology has long faced a paradox: the elegant idea of a universe born from 'nothing' relentlessly favored dreary microscopic worlds. New research shows that swapping the familiar sphere for a three-dimensional torus rewrites the script. Summing over all possible smooth fillings of the toru
arXiv:2605.05317v2 · 2026-05-06

Curved Cosmos: The Secret Life of the Local Universe

Using Cosmicflows-4++, scientists directly estimated relativistic corrections and found that curvature contributes about 10% to the expansion dynamics on scales up to 300 Mpc/h, while kinematic backreaction is negligible. This challenges the globality of ΛCDM and threatens systematic errors in cosmo
arXiv:2605.05454v1 · 2026-05-06

The Invisible Artist: How Dark Matter Distorts Portraits of Black Holes

Simulating black hole images against different dark matter profiles revealed a frightening flexibility: a cored-NFW-type flattened halo noticeably inflates the bright ring, shifts its center, and amplifies asymmetry — almost exactly replicating real Event Horizon Telescope data. The Einasto profile,
arXiv:2605.05635v3 · 2026-05-07

The Singularity That Never Was: How Quantum Tango Erases the Beginning of the Universe

In quantum cosmology, the Big Bang singularity turns out to be a mirage. Using relational time emerging from entanglement between subsystems of the universe, physicists have shown: the probability of zero volume is strictly zero. The Page-Wootters formalism transforms a static wave function into an
arXiv:2605.06093v1 · 2026-05-07

When Gravity Knits Quantum Lace: Lessons from the Schrödinger–Newton Model

The hybrid Schrödinger–Newton equation for the first time analytically disentangled two faces of gravity: self-interaction and mutual attraction. It turns out that self-gravity does not alter the Schmidt spectrum, and hence the measure of quantum entanglement; however, the pairwise potential activel
arXiv:2605.06577v1 · 2026-05-07

Fuzzy-nova: A Quantum Wave Dissolving Black Holes

According to classical theory, the collapse of a massive star ends in a black hole with a singularity, where the curtain of physical laws falls. Roger Penrose proved the inevitability of singularities, and Stephen Hawking showed that quantum effects create the information paradox. New work proposes
arXiv:2605.07848v2 · 2026-05-08

The Funeral March of Negative Mass: Why LIGO Doesn't Hear Anti-Chirps

A new study proposes a simple observational test: any binary system with a negative-mass component must either produce an anomalous signal with a falling frequency or instantly fly apart. Not a single such 'note' has been found in the LIGO, Virgo, and KAGRA archives. The silence shuts down an entire
arXiv:2605.10976v1 · 2026-05-08

Symphony of Collapse: The Algebraic Key to Black Holes

At the heart of a dying star lies an algebraic cipher that translates the language of matter into the language of black hole geometry. Physicists have found a precise two-way map: given a density profile, you can recover the exterior metric—and vice versa—without solving complex differential equatio
arXiv:2605.08807v1 · 2026-05-09

Cosmic Instrument: Resonant Songs of Rotating Wormholes

By numerically investigating the scattering of scalar waves on a rotating traversable wormhole, scientists discovered Breit-Wigner resonances. They sharply intensify under fast rotation and for counter-rotating modes, creating a spectral fingerprint radically different from that of black holes—a sig
arXiv:2605.09426v1 · 2026-05-10

Universes in Wine Glasses: How Wormholes Reconciled the Irreconcilable

The study unites two poles of quantum cosmology: tunneling from existing space and the no-boundary Hartle–Hawking state. Numerical solutions of Einstein's equations with an axion (or magnetic) charge and a scalar field revealed a family of Euclidean wormholes—their scale-factor profile shaped like a
arXiv:2605.10548v1 · 2026-05-11

Astrons: Electric Leviathans That Defy Cosmology

Astrons — hypothetical relics of the early Universe with a mass on the order of 10¹² solar masses and a gigantic electric charge — could explain dark energy. However, rigorous analysis crushes the simple hopes: ordinary accretion does not yield the required charge, and phenomenologically interesting
arXiv:2605.10587v1 · 2026-05-11

Quantum Tremor of Parallel Worlds: Gravity on a Laboratory Table

A new theoretical work unites quantum mechanics and general relativity, showing that two parallel atomic lasers, unperturbed in the classical world, begin to diverge under the influence of quantum fluctuations of spacetime. Vacuum tremors of the metric give rise to an irreducible spread of trajector
arXiv:2605.11035v1 · 2026-05-11

Cosmic Crystal: How Vacuum Defects Twist Light

The cosmic microwave background not only brings a map of the early universe but also a subtle twist in polarization—just a few thousandths of a radian. For a long time, it was attributed to ultralight axions, but they clash with experiments. A new explanation is more elegant: the rotation arises whe
arXiv:2605.11065v1 · 2026-05-11

The Horizon's Silent Roar: The Fading Ring of Analog Black-White Holes

A new theoretical study demonstrates how analog black-white holes created in superconducting SNAIL chains respond to perturbations: they don’t explode, but quietly fade, emitting a pure dissipative tone. Supersymmetric quantum mechanics proves the absence of growing modes, and quasinormal frequencie
arXiv:2605.11565v1 · 2026-05-12

Cosmic Spinning Top: Gravity vs. Quantum Superpositions

Mass currents have now been introduced into the Diósi–Penrose wave function collapse model for the first time, adding post-Newtonian corrections from general relativity. It turns out that moving mass generates gravitomagnetic noise, causing angular momentum decoherence. The most dramatic effects app
arXiv:2605.12172v1 · 2026-05-12

The Silent String of Gravity: Hunting for κ

The weak equivalence principle has been tested with fantastic precision, but always with grounded samples — as if one string of the gravitational violin is deliberately muted. The κ parameter quantifies whether acceleration depends on electric charge: it is the ratio of the difference in acceleratio
arXiv:2605.12246v2 · 2026-05-12

Black Holes: The Perfect Mask of the Abyss

All the headline discoveries — from mergers detected by LIGO to the image of M87*’s shadow — are interpreted as direct proof of black holes’ existence. But a careful analysis shows that the same signatures arise from any ultracompact horizonless object, if its radius differs from the gravitational r
arXiv:2605.13901v1 · 2026-05-12

Gravitational Radio Forest: How a Hydrogen Quantum Detector Reveals Dark Matter

Astrophysicists have proposed a new method for hunting dark matter — not searching for the black holes themselves, but listening to the quantum echo of gravity. In regions of ionized hydrogen, tidal forces from primordial black holes split the atomic level 2P₃/₂, turning a single 9.9 GHz absorption
arXiv:2605.13042v1 · 2026-05-13

The Angular Momentum Symphony: When Weak Gravity Is Strong

The diagnostic parameter \(\tilde{\alpha}\) reveals that in galaxies and clusters, the post-Newtonian approximation loses reliability due to accumulated nonlocal gravitational correlations. Its value skyrockets precisely where dark matter is traditionally invoked—and this finding could overturn our
arXiv:2605.13557v1 · 2026-05-13

Orbital Web: Why the Big Rip Will Wait at Least 30 Years

Cosmology allows for a terrifying scenario of phantom dark energy, where the universe's expansion accelerates so violently that it tears apart galaxies, stars, and atoms. Deep-space detectors can't spot a sudden shift to this state: light from distant supernovae has traveled billions of years. So Ro
arXiv:2605.13705v1 · 2026-05-13

Universe from a Wine Glass: How Wormholes Ignite Inflation

New calculations in quantum cosmology show that Euclidean wormholes with a throat — so-called 'wine glasses' — can dominate the path integral, setting the initial conditions for the Big Bang. Unlike the classical Hawking–Hartle scenario, these topologically nontrivial solutions naturally lead to inf
arXiv:2605.13777v2 · 2026-05-13

Geometry's Verdict: Why Wormholes Are Doomed to Exoticity

The no-go theorem dashes hopes of circumventing the wormhole paradox: no interaction with dark energy can shield against the geometric demand for 'negative pressure.' The work shows that even the most cunning models with energy transfer between matter and vacuum shatter against the relentlessness of
arXiv:2605.14027v1 · 2026-05-13

Graviton Laser: Translating Gravity into the Language of Light

The main obstacle for a graviton laser is that gravitational waves cannot be reflected: they pass through any substance. The solution lies in the Gertsenshtein effect. Under a powerful magnetic field, gravity particles temporarily become photons, which are easily reflected by ordinary mirrors. The r
arXiv:2605.14050v1 · 2026-05-13

Long-Throat Wormholes: How Doppler Notes Give Them Away

New research shows: wormholes with a precisely tuned throat length can cast a shadow indistinguishable from that of a Schwarzschild black hole. But numerical simulations expose a critical flaw in the disguise—the wormhole's accretion disk emits far more energetic radiation thanks to Doppler boosting
arXiv:2605.16413v2 · 2026-05-13

Gravitational Echo: How Black Holes Weave a Quantum Web of Gravitons

Quantum gravity eludes experiments due to the Planck scale. But the 2026 Gravity Research Foundation award-winning work points to a natural super-amplifier: superradiant axion clouds around rotating black holes. This cosmic mechanism generates squeezed states with up to 10⁷ correlated gravitons, cre
arXiv:2605.14797v1 · 2026-05-14

The Devourer Universe: Dark Energy from World Mergers

In a new cosmological model, the source of accelerated expansion is not a mysterious cosmological constant but the process of absorbing other universes. The merger intensity is set by a single constant g, calibrated by the local value of the Hubble constant. The computed evolution of the dark energy
arXiv:2605.15045v1 · 2026-05-14

Invisible Drums: How Gravitational Waves Give Birth to Black Holes

A mechanism is proposed in which gravitational waves from bubble collisions during phase transitions and domain wall annihilation induce second-order scalar inhomogeneities. These inhomogeneities can collapse into primordial black holes of asteroid masses, fully accounting for dark matter. Model-ind
arXiv:2605.15197v1 · 2026-05-14

Cosmic Bellows: How Eternal Inflation Resurrects the Universe from the Ashes

The new model intertwines cyclic cosmology and inflation into a single dance: two scalar fields, like blacksmith’s bellows and a valve, alternately compress and inflate the Universe. This approach not only lifts the curse of the singularity but also explains the mysterious smoothness of the cosmos,
arXiv:2605.15374v1 · 2026-05-14

Light Leaks into Darkness: How Photons Become Dark Matter

Two key methods for measuring the expansion rate of the Universe — the cosmic microwave background and supernovae — yield values differing by 5 sigma. A hybrid model adds to the cosmological redshift a contribution from quantum conversion of photons into hidden mass. Analysis of the Pantheon+SH0ES c
arXiv:2606.02097v1 · 2026-06-01

The Snapping Cable of Reality: How Finite String Thickness Accelerates Quantum Decay and Reshapes the Gravitational Hum

In the early Universe, the Big Bang could have spawned cosmic strings—one-dimensional defects whose enormous energy can still shake spacetime. Their decay through quantum tunneling dictates the gravitational signal that detectors will pick up. New lattice modeling has shown: the string's finite thic
arXiv:2606.03008v1 · 2026-06-02

The Neutron Kitchen of the Big Bang: How Black Holes Tidied Up Lithium-7

The primordial lithium-7 problem is one of the main contradictions in standard cosmology: Big Bang nucleosynthesis theory predicts three times more lithium-7 than observed in old stars. An elegant solution proposes using neutrons from the evaporation of primordial black holes. Neutron capture turns
arXiv:2606.03316v2 · 2026-06-02

Roots from the Abyss: The Secret Growth of Supermassive Black Holes

Astronomers are increasingly finding giant black holes in the early universe, with masses reaching a billion suns. Ordinary gas accretion can't 'fatten' them up fast enough. A new hypothesis introduces an extra dimension: our brane-universe and an invisible donor brane intersect at a shared horizon.
arXiv:2606.03414v1 · 2026-06-02

Cosmic Detective: Two Independent Clues Against the Main Cosmological Debate

The Hubble constant — the expansion rate of the universe — has become a bone of contention: data from the cosmic microwave background and the distance ladder diverge by 6 sigma. Astrophysicists have proposed a new arbitration by cross-breeding 142 gravitational-wave events from the GWTC-4 catalog wi
arXiv:2606.03634v1 · 2026-06-02

Echoes of Black Holes: How Gravitational Sirens Reveal the Curvature of the Universe

Gravitational waves from mergers of black holes and neutron stars are not just ripples of curved spacetime but precise 'standard sirens' for measuring distances. A new study demonstrates that the Cosmic Explorer and Einstein Telescope detectors will be able to determine curvature Ω_k with an error o
arXiv:2606.04216v1 · 2026-06-02

Lead Archives: Ancient Minerals vs. Higgsino

Dark matter is physics' greatest intrigue. Paleodetection opens a new chapter: million-year-old minerals, like laurionite (PbClOH), preserve traces of dark particles. Thanks to massive lead nuclei and exceptional purity, crystals can detect the Higgsino — the superpartner of the Higgs boson, whose s
arXiv:2606.05299v1 · 2026-06-03

Plateau and Dip: The Music of Cosmic Strings

Two unrelated puzzles of the Standard Model — the flavor hierarchy and the strong CP problem — find a common solution in a model with flavor gauge symmetry and an axion. Born in the early Universe, two types of cosmic strings after the QCD phase transition become efficient sources of gravitational w
arXiv:2606.05320v1 · 2026-06-03

Tiny Sparks That Ignited the Universe

A natural gravitational lens—the Abell 2744 cluster—boosted JWST's ultra-deep observations and allowed the selection of a population of compact galaxies with an equivalent width of [OIII]+Hβ >740 Å. NIRSpec spectroscopy confirmed: their metallicity is 10–100 times lower than solar, dust is almost ab
arXiv:2606.05323v1 · 2026-06-03

Vacuum Tide: How Cosmic Emptiness Conducts the Universe

Standard cosmology stumbles over a 120-order abyss: by quantum calculations, vacuum energy should incinerate the universe, yet we see only a smoldering ember. The Running Vacuum Model (RVM) bridges the gap: it teaches spacetime to “remember” the expansion rate. In curved geometry, quantum fluctuatio
arXiv:2606.05352v2 · 2026-06-03

The Cosmic Metronome Falls Out of Rhythm: Dark Energy Rewrites Hubble's Symphony

The DESI instrument, mapping millions of galaxies, has picked up signs of dark energy evolution. This discovery rewrites the rules for measuring the Universe's expansion rate: the local Hubble constant might drop by several km/s/Mpc. The drama of the Hubble tension — the discrepancy between the earl
arXiv:2606.05358v1 · 2026-06-03

The Neutrino Chord: How a Supernova Will Unveil the Hidden Mass Order

The next galactic supernova is a rare gift to astrophysics, capable of answering a key particle physics question in a fraction of a second. Analysis of two independent signals—the sharp peak of electron neutrinos in the first milliseconds and the rise rate of the electron antineutrino flux—points to
arXiv:2606.06580v1 · 2026-06-04

Dark Start: How Vacuum Decay Birthed the Big Bang

Imagine: after inflation, the Universe didn't ignite right away — it plunged into darkness. Nearly all the energy went into a dark sector, while ordinary matter got stuck in a false vacuum — a supercooled state, like liquid glass on the verge of crystallizing. Then a quantum nudge spawned bubbles of
arXiv:2606.06587v1 · 2026-06-04

PeVatron's Hybrid Orchestra: A Particle Symphony at the Edge

Astrophysicists have built a self-consistent model of the source LHAASO J1849-0002, associated with the pulsar PSR J1849-0001. In the hybrid scenario, relativistic electrons from the pulsar wind nebula scatter the cosmic microwave background, while protons collide with a nearby molecular cloud, prod
arXiv:2606.06974v1 · 2026-06-05

The Cosmic Hump: How a New Spectrum Creates Massive Galaxies at the Dawn of Time

Observations by the James Webb Space Telescope have shown that in the early Universe, there are tens to hundreds of times more massive galaxies than standard cosmology allowed. A new model offers a paradoxically simple solution: a tiny 'hump'—a local enhancement—in the spectrum of primordial perturb
arXiv:2606.07357v1 · 2026-06-05

The Celestial Forge: How Proton Beams Take the Shape of a Hammer

Data from the Parker probe, plunging into the very furnace of the solar wind, brought a mystery: proton beams there often have a hammer shape. To understand how this happens, scientists ran hybrid simulations, treating protons as particles and electrons as a fluid. By comparing two regimes differing
arXiv:2606.07838v1 · 2026-06-05

Cosmic Tuning Fork: KLT-Net Neural Network Rewrites the Distance Ladder

Using 1701 Type Ia supernovae, the KLT-Net neural network reconstructs distance modulus for the first time without relying on cosmological models. The harmony of three architectures—KAN, LSTM, and Transformer—captures both local nuances and the global rhythm of expansion. The result: Hubble constant
arXiv:2607.06959 · 2026-07-08

Anchor in the Shallows: Why DESI Data Misses the Universe's Acceleration

Is the Universe accelerating its expansion—or not? The latest DESI survey, combined with Planck cosmic microwave background data, yields no clear answer for the current epoch, unlike older SDSS data. Researchers have shown that the root of the discrepancy is DESI's lack of measurements at low redshi
arXiv:2607.07348 · 2026-07-08

Cosmic Calligraphy: A General-Purpose Neural Network Catches Fast Radio Bursts

Fast radio bursts—ultra-short but colossally powerful radio flashes from distant galaxies—leave an elegant curved trace on spectrograms, resembling a calligraphic flourish. For decades they were hunted with heavy algorithms and narrow neural networks, until the most unexpected tool was tried: a mult
arXiv:2607.07382 · 2026-07-08

Music of the Spheres: How LISA Will Hear Dark Matter's Duet

Researchers assessed the capability of the space-based gravitational-wave observatory LISA (launch in 2035) to detect ultralight dark matter interacting with Standard Model fields via quadratic coupling—a common mechanism in axion and dilaton models. Through this interaction, the signal emerges on t
arXiv:2607.08248 · 2026-07-09