Phenomenology
of Higher-Order Gravity Theories| Phenomenology
of Higher-Order Gravity Theories |
Solutions > s.a. Birkhoff's
Theorem; schwarzschild; wormholes.
* In general: All solutions
of the ordinary Einstein equation still extremize S, and there are
other solutions; However, if S does not include the usual R term,
the ordinary solutions do not couple to positive-definite matter sources.
* Features: In some theories,
torsion and its conjugate momentum play an important role.
* Results: Birkhoff's
theorem in general is not valid, but it is in some cases; There is massive
radiation (2 Yukawa potentials, 8 degrees of freedom, the usual spin-2 graviton,
a massive one – negative
energy – and
one scalar field); It is claimed that in theories with purely quadratic terms
in
the action, the energy is identically zero, but this seems strange (RDS).
@ Gravitational waves: Campanelli & Loustó PRD(96)gq/95 [shock
waves]; de Rey et al CQG(03)gq,
CQG(03)gq,
CQG(04)gq/03;
Ananda et al PRD(08)-a0708 [4th-order
gravity in FRW]; Corda a0710-in
[R–1 theory]; > s.a. gravitational
wave background.
@ Types of solutions: Campanelli et al PRD(94)gq [perturbative
method]; Barraco & Hamity GRG(99)
[asymptotically flat, and general relativity solutions]; Clifton & Barrow PRD(05)gq [Gödel,
Einstein and de Sitter], CQG(06)
[Kasner-type], CQG(06)gq [cosmological,
4th-order theories]; Goswami et al a0804 [Einstein universes, 4th-order theories]; > s.a. spherical
symmetry.
Cosmology > s.a. acceleration;
expansion; cmb; friedmann
equation; FRW spacetime; Gauss-Bonnet
Gravity; higher-order
gravity.
* Cosmic no hair theorem: Within fourth order gravity
with L = R + R2,
the inflationary phase turns out to be a transient attractor.
* R–1 theories:
They lead to cosmological acceleration, which is part of their motivation;
A 1/R term by itself is ruled out by constraints on scalar-tensor
gravity, but could work as an
extra contribution to the action.
@ R2 theories: Cárdenas
et al MPLA(03)gq [and
inflation]; Meng & Wang GRG(04), CQG(05)gq/04, GRG(05)
[Palatini, and inflation]; Debnath & Paul IJMPD(06)gq/05
[varying G and cosmological constant].
@ R–1 theories: Nojiri & Odintsov
PRD(03)ht [inflation & acceleration];
Meng & Wang CQG(03)ap;
Mena et al PRL(06)ap/05 [and
supernovas; news pw(06)feb];
Poplawski CQG(06)gq/05 [acceleration],
CQG(06)gq/05 [present
and late universe]; PLB(06)gq [jerk
parameter]; DeDeo et al a0712-PRL
[stable accelerating universe from f(R) = R 
4/R].
@ ln R theories: Nojiri & Odintsov GRG(04)ht/03 [and
acceleration].
@ Arbitrary f(R): Carroll
et al PRD(05)ap/04;
Zhang PRD(06)ap/05 [large-scale
structure]; Sotiriou CQG(06)gq/05 [positive
and negative powers of R]; Carloni et al CQG(06)
[bounce conditions]; Poplawski PRD(06)gq [and
dark energy]; Brookfield et al PRD(06)ht [trinomial
in R, cosmology and 5th force]; Fay et al PRD(07)ap;
Li & Barrow PRD(07)gq [metric];
Zhang PRD(07)ap
[solar system + galaxies]; Fay et al PRD(07)gq,
Appleby & Battye PLB(07)-a0705 [and 
CDM
cosmology]; Rahvar & Sobouti a0704-PRL
[f from acceleration]; Koivisto a0706 [Palatini
+ generalized dark matter]; De Felice et al PRD(08)-a0706 [bounds
on parameters]; Starobinsky JETPL(07)-a0706 [effective
cosmological constant in some solutions]; Song et al PRD(07)-a0706 [acceleration
and cmb].
@ f(R) theories, expansion and acceleration:
Samart ap/06;
de la Cruz-Dombriz & Dobado PRD(06)gq;
Amendola et al PRL(07)ap/06,
IJMPD(07)ap/06, PRD(07)
[ruled
out by wrong
expansion rate]; Rador PRD(07)ht;
Nojiri et al a0705-PLB
[f(R)-scalar-Gauss-Bonnet];
Cognola et al PRD(08)-a0712;
Lee a0801-MPLA;
Nojiri & Odintsov a0801-in
[dark matter, dark energy and inflation]; Appleby & Battye JCAP(08)-a0803;
Carvalho et al a0804.
@ Ricci-squared theories: Allemandi et al PRD(04)ht [Rab Rab lagrangians];
Li
et al PRD(07)-a0707 [R + f(Rab Rab)];
Cotsakis & Tsokaros PLB(07)
[radiation-dominated, flat FRW].
@ Singularities: Middleton & Barrow PRD(08)-a0801 [isotropic
singularity, stability]; Höffer von Loewenfeld & Sachs a0803 [resolution].
@ Other cosmology: Brüning
et al GRG(94)gq [non-analytic,
and inflation]; Fukuma et al PTP(01)ht [AdS-cft];
Ezawa et al CQG(03)gq;
Carloni et al CQG(05)gq/04 [Rn];
Comelli & Dolgov JHEP(04)
[determinant gravity];
Lambiase & Scarpetta PRD(06)ap [baryogenesis];
De Felice & Hindmarsh JCAP(07)-a0705 [unsuccessful
class of theories]; Abdelwahab et al CQG(08)-a0706 [exp{–R/}
gravity]; > s.a. bianchi
models; cosmological
perturbations.
Other Phenomenology > s.a. black
hole formation, laws and
solutions; phenomenology
of gravity; tests
of general relativity.
* Stability: Certain
f(R) theories can stabilize solutions which are unstable
in general relativity, such as the Einstein static universe.
@ General references: Capozziello & Francaviglia GRG(08) [rev].
@ Stability: Schmidt PRD(94);
Ezawa et al CQG(99)
[higher-dimensional, semiclassical];
Dolgov & Kawasaki ap/03 [R–1 theories];
De Felice et al JCAP(06)ap [superluminal
mode propagation]; Faraoni PRD(06)ap,
Sotiriou PLB(07)gq/06,
Sawicki & Hu PRD(07)ap [f(R)
theories]; Sokolowski CQG(07)gq [interpretation
and viability]; Böhmer et al PRD(07)-a0706 [Einstein
static universe]; Lee a0710.
@ Galactic dynamics: Capozziello et al PLA(04), ap/04-in,
Frigerio & Salucci ap/07/MNRAS
[rotation curves]; Borowiec et al ap/06-in
[dark matter and dark energy].
@ Solar system constraints: Olmo PRL(05)gq, PRD(05)gq + gq,
Jin et al gq/06 [f(R)];
Faraoni PRD(06)gq;
Ruggiero
& Iorio JCAP(07)gq/06 [planetary
orbits]; Chiba et al PRD(07)ap/06;
Zakharov et al PRD(06);
Faulkner et al PRD(07)ap/06,
Saffari & Rahvar PRD(08)-a0708 [and
cosmology]; Hu a0705 [models
that evade solar system tests]; Allemandi & Ruggiero GRG(07);
Bertolami & Paramos a0709;
Iorio & Ruggiero a0711;
Capozziello & Tsujikawa PRD-a0712.
@ R–1 theories: Flanagan
PRL(04)ap/03,
Vollick CQG(04)gq/03,
Kremer & Alves PRD(04)gq [Palatini
form]; Soussa & Woodard GRG(04)ap/03 [force
of gravity]; Vollick
PRD(05)gq/04 [with
Dirac field]; Shao et al PLB(06)gq/05 [as
correction term]; Erickcek et al PRD(06)ap
[ruled out by solar system tests].
@ Other theories: Clifton & Barrow PRD(05)gq [R1+a Lagrangian];
Navarro
& Van Acoleyen JCAP(06)ap [ln f(R),
dark energy and MOND].
@ Newtonian limit: Quandt & Schmidt AN(91)gq/01;
Domínguez & Barraco
PRD(04)gq [Palatini];
Capozziello gq/04-in
[rev]; Capozziello & Troisi PRD(05)ap
[4th-order, PPN limit]; Sotiriou GRG(06)gq/05;
Bertolami et al PRD(07)-a0704 [extra
force]; Capozziello et al PRD(07)-a0708.
@ Newtonian limit, R–1:
Dick GRG(04)gq/03;
Rajaraman ap/03;
Navarro
& Van Acoleyen PLB(05)gq [and
acceleration]; Cembranos PRD(06)gq/05 [as
lim at intermediate energy]; Navarro & Van Acoleyen JCAP(06)gq/05 [large
distance].
@ Post-Newtonian framework:
Allemandi et al GRG(05);
Capozziello et al gq/06 [and
experimental constraints].
@ Star interiors in f(R) gravity: Kainulainen et al
PRD(07)-gq/06;
Bustelo
& Barraco
gq/06/CQG;
Henttunen
et al PRD(08)-a0705.
@ Singularities: Holdom PRD(02)
[and horizons]; > s.a. types of singularities [isotropic].
@ Related topics: Accioly
et al NCB(00), Accioly & Blas PRD(01)gq [light
deflection, quadratic]; Magnano & Sokolowski AP(03)gq/02 [massive
spin-2 field generated]; Núñez & Solganik PLB(05)ht/04 [IR
modifications not viable]; Gabadadze & Iglesias PLB(06)
[precession]; Capozziello et al MPLA(07)
[gravitational
wave background]; Iorio & Ruggiero IJMPA(07)
[double pulsar]; Li et al a0801 [indistinguishable
macroscopic behavior]; > s.a. Chameleon Field; energy
conditions; equivalence
principle; gravitational
radiation; thermodynamics.
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22 jun 2008