Tests of Newtonian Gravity  

In General > s.a. branes; equivalence principle; gravitational constant; experiments [Cavendish]; phenomenology.
* Idea and motivation: Various theories have occasionally predicted departures from Newton's r–2 law; In particular, brane-world models with "large" extra dimensions predict departures at macroscopically small scales.
* Radial dependence: Small-scale deviations from the inverse-square law could be evidence for higher dimcnsions.
* Status: 2001, So far the r–2 law seems ok; Long tested in the lab for L ~ 1 m with Cavendish-type experiments; Recently verified down to 150 microns with torsion balances; Orbital measurements of satellites and planets cover distances of the order of 100 km or more, and galactic considerations give λ > 1019 m; Recent geophysical experiments are bridging the gap, but results are still controversial (some indicate a value of G about 1% higher than expected, and/or a Yukawa-type component, but the method has been criticized); 2004, Large-scale structure surveys find no departure at 1023-m scales, lab tests from 137 microns still consistent with Newtonian gravitation; 2007, Torsion balance experiments find no deviation down to 56 microns.
* Gravity gradients: 1998, The most precise measurements, 10–10 g/m, are done with atom interferometers.
@ News: Snadden et al PRL(98) + pn(98)jul [gradients]; news pn(00)may [Adelberger et al, r2].
@ Overviews: Gillies AJP(90)jun [RL], ed-92; in Ohanian & Ruffini 94; Adelberger et al ARNPS(03)hp + pw(05)apr; Gundlach NJP(05) [lab tests].

Small-Scale Tests > s.a. casimir effect; general relativity.
* Methods: 2018, Torsion-balance experiments cannot probe gravity at very short distances, the current limit being about 0.01 mm.
@ General references: Long & Price CRP(03)hp [rev]; Azam PRD(08)-a0712 [brane-motivated violations of Birkhoff theorem].
@ Millimeter range: Long et al NPB(99), hp/00-MG9 [below 1 mm]; Hoyle et al PRL(01) [down to 218 μm]; Long et al Nat(03)feb + pw(03)feb [108 μm]; Paik et al GRG(04) [in space]; Hoyle et al PRD(04)hp [137 μm to 10.77 mm];
@ Micrometer range: Krause & Fischbach IJMPD(01), Chiaverini et al PRL(03) [below 0.1 mm]; Dimopoulos & Geraci PRD(03) [proposal to use BEC]; Speake et al GRG(04) [L ~ 1 μm?]; Smullin et al PRD(05)hp [6–20 μm]; Ferrari et al PRL(06) + pn(06)aug [Bloch oscillations in 88Sr]; Kapner et al PRL(07) + pw(07)jan [down to 56 μm ok]; Tu et al PRL(07) [down to 66 μm ok]; Weld et al PRD(08)-a0801 [apparatus]; Geraci et al PRD(08)-a0802 + news pw(08)mar [bounds at 10 μm]; Masuda & Sasaki PRL(09) [0.48–6.5 μm range]; Sushkov et al PRL(11) [new bound between 0.4 and 4 μm]; Exirifard a1207 [enhancement around the gravitational saddle points of the Solar System]; Jenke et al PRL(14)-a1404 [gravity resonance spectroscopy constraints, dark-energy chameleon field and dark matter axion-like spin-mass coupling]; Tan et al PRL(16) + news forbes(16)apr; Luo et al a1607-conf; Antoniou & Perivolaropoulos a1708 [constraints on spatially oscillating forces]; news pw(18)jan [using neutron scattering off noble-gas nuclei].
@ Nanometer range: Fischbach et al PLA(03) [iso-electronic effect]; Nesvizhevsky & Protasov CQG(04) [from neutron quantum states]; Klimchitskaya & Mostepanenko G&C(14)-a1403 [new constraints from measurements of the Casimir force].
@ Special effects: Camacho IJMPA(01)gq/00 [on quantum interference], PLA(01) [on light coherence].
@ Related topics: Fucito gq/00-conf [large and small scales]; Arun et al CQG(06) [with gravitational-wave observations]; Adelberger et al PRL(07) [constraints on dilaton, radion, chameleon and Yukawa interactions]; > s.a. Chameleon Field; neutrons.

Intermediate-Scale Tests > s.a. modified newtonian gravitation [including PPN formalism].
@ Lab-based macroscopic range: Beane GRG(97) [0.1 mm – 1 cm]; Steffen IJMPD(04)gq/05 [10 cm, proposed experiment]; Trenkel PRD(08) [2 cm – 1 m, constraints on Yukawa term]; news pw(09)dec [measuring g in the lab with a quantum atom "trampoline"]; Meyer et al GRG(12)-a1112 [and MOND, small accelerations]; Klimchitskaya et al PRD(13)-a1306 [constraints on Yukawa term from measurements of Casimir interactions between metallic surfaces].
@ Earth scales: Ander et al PRL(89) [Greenland ice]; Kim PLB(89) [re anomalies]; Thomas PRD(89) [analysis]; Fischbach & Talmadge AJP(91)mar; Fischbach & Talmadge 99; Baldi et al PRD(01) [lake water]; Ducheyne AHES(10) [history, experiments between 1798 and 1898]; > s.a. Gravimeter.
@ Special effects: Boynton CQG(00) [torsion pendulum]; Mohazzabi & James AJP(00)nov [plumb line deviation]; Camacho IJMPA(01)gq/00 [interferometry]; Betrisey & Roehner a1306 [effect of the Moon on pendulum periods].

Large-Scale Deviations > s.a. MOND [tests].
* Cosmology: General relativistic cosmological solutions, even in the presence of pressure, can be mimicked by using neo-Newtonian hydrodynamics.
@ Solar-System scales: Dvali et al PRD(03) [Lunar-ranging tests of cosmologically-motivated theories]; Kolosnitsyn & Melnikov GRG(04) [orbit precession]; Reynaud & Jaekel IJMPA(05)gq-in [and Pioneer anomaly]; Li & Zhao IJMPD(05)gq [1.2 × 107 – 3.8 × 108 m, satellite-lunar]; Wallin et al ApJ(07)-a0705 [bounds from TNO orbits]; Iorio JHEP(07)-a0708 + pw(07)aug [no modifications on scales larger than 0.1 AU]; Iorio SRE(08)-a0809 [Yukawa-like]; Bovy et al ApJ(10)-a0903 [other power laws]; Buscaino et al PRD(15)-a1508 [tests up to 100 AU].
@ Galactic scales: Camacho GRG(04)gq/03 [1014 m, Sagnac interferometry]; Zucker et al ApJL(06)ap/05 [motion around Milky Way center]; Brandao & de Araujio GRG(09)-a0910 [Yukawa-like potentials and galactic dynamics]; Scarpa et al A&A(11)-a1008 [globular clusters].
@ Cosmological scales: Uzan IJTP(03); Sealfon et al PRD(05)ap/04 [Mpc, from large-scale structure]; Shirata et al PRD(05)ap, PRD(07)-a0705 [from galaxy clustering]; Sereno & Peacock MNRAS(06)ap [mass density fluctuations].

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