Causality Violations| Causality Violations |
In General > s.a. information; wave
phenomena.
* Ways to violate causality:
Superluminal local travel from classical physics (tachyons, ...), due to quantum
effects (quantum tunneling, quantum field theory effects),
"global" effects due to non-trivial spacetime topology (wormholes,
Misner space, ...); Superluminal travel requires violations of the averaged
null energy
condition.
@ General references: issue disc(89)jun;
Nahin 98; Gott 01; Davies 01; Toomey 07 [r pw(08)jan].
@ Detection: Haque & Joglekar JPA(09)-a0808 [non-local
scalar model].
@ Philosophical: Smith BJPS(97)
[slipping on banana peels]; Dowe PhSc(03)jul
[coincidences]; Raju FP(06)-a0804 [time
travel and spontaneity].
Classical, Local Superluminal Signaling and Travel > s.a.
causal; tachyons; wave phenomena.
@ Books: Fayngold 02; Tiwaru 03.
@ General references: Svozil PLA(95)
[paradoxes]; Recami et al IJMPA(00)
[and special relativity]; Recami FP(01)phy [review];
Zhou PLA(00)
[vg > c,
numerical]; Fayngold 02; Liberati et al AP(02)gq/01 [Scharnhorst
effect]; Van Flandern & Vigier
FP(02)
[support]; Lobo & Crawford LNP(03)gq/02 [definitions];
Krasnikov PRD(03)gq/02 [quantum
inequalities and shortcuts]; Buenker SJCP(04)phy [??];
Nimtz FP(04);
Bonvin et al a0706 [superluminal
motion and causality].
@ Specific theories: Hashimoto & Itzhaki PRD(01)
[solitons in non-commutative gauge theory]; Borghardt et al PLA(03)qp [vg > c
in Klein-Gordon]; González-Mestres ap/04-in
[non-tachyonic "superbradyons"]; > s.a. Pauli-Fierz
Theory.
Non-Causal Spacetimes > s.a. gödel
spacetime;
Misner Space; types
of spacetimes [3D
flat]; wormholes.
* Consequences: If CTCs
existed, quantum computers would be no more powerful than classical computers.
@ General references: Tipler PRD(74), PRL(76);
Penrose in(79); Thorne in(91);
Deser & Steif gq/92 [3D
results]; Blau AJP(98)mar
[and topology change]; Romero & Torres MPLA(01)gq [consistency];
Garay & González-Díaz
GRG(01)
[and quantum gravity]; Bonnor IJMPD(03)gq/02 [conceptual];
Lobo & Crawford gq/02-in
[rev]; Shore IJMPA(03)gq/02 [rev];
Susskind gq/05 [unlikely],
rebuttal gq/05;
Monroe FP(08)gq/06 [and
topology]; Bonnor GRG(09)
[size of region for spinning bodies].
@ Examples: Chamblin et al PRD(94),
Yurtsever GRG(05)gq/94 [Politzer
spacetime]; Caldarelli et al JHEP(01)
[in AdS5];
Bonnor CQG(02)
[asymptotically flat example], Rebouças & Teixeira IJMPA(98)gq [Kaluza-Klein
theory]; Olum & Everett FPL(05)
[re circulating light beam]; Bonnor & Steadman GRG(05)
[Einstein-Maxwell]; Rosa & Letelier a0706 [cylindrical
with spinning sources, stability of closed timelike curves].
@ Initial-value problem: Friedman & Morris PRL(91),
in(91); Fewster et al PRD(96)gq;
Friedman gq/04-in
[rev]; Aref'eva et al TMP(08)
[waves].
@ Chronology protection: Hawking PRD(92);
Visser PRD(93), NPB(94)ht/93;
Cassidy & Hawking PRD(98)ht/97 [models];
Huang PRD(99)ht/02 [in
Gödel spacetime]; Hiscock gq/00;
Visser gq/02-in
[re]; Friedman & Higuchi AdP(06), a0801 [rev];
Monroe gq/06 [censorship];
Segre
gq/06 [comment]; > s.a.
wormholes.
@ And singularities: Maeda & Ishibashi PRD(97) [spatially compact].
@ And energy conditions: Ori PRL(91),
PRL(93); Olum PRL(98)gq;
Visser et al NPPS(00)gq/98;
Baird gq/99.
@ Paradoxes: Krasnikov PRD(97)gq/96,
PRD(02)gq/01;
Dowe PhSc(07)dec; > see
in quantum mechanics below.
@ Related topics: Cooperstock & Tieu gq/04,
FP(05)
[misconceived
article?]; Hadley gq/06-in
[and quantum theory]; Durham a0803 [and
quantum information]; > s.a. klein-gordon
fields.
Time Machines > s.a. wormholes [including
Krasnikov tube].
@ General references: Novikov JETP(89);
Krasnikov
CQG(94),
PRD(96)gq/95 [quantum
stability], CQG(98)gq/97 [singularity-free],
PRD(98)gq/95,
PRD(99)gq/98 [and
quantum field theory], CQG(02)gq/01 [no-go
in classical general relativity], gq/03-in
[rev]; Carlini et al IJMPD(95),
Carlini & Novikov IJMPD(96)
[self-consistency]; Low CQG(95);
Woodward FPL(95);
Davies SA(02)sep; Krasnikov gq/06 [intro].
@ Gott time machines: Gott PRL(91)
[moving cosmic strings]; Carroll et al PRL(92),
Deser
et al PRL(92)
[obstacles]; Holst GRG(96)gq/95 [in
AdS]; Birmingham & Sen PRL(00)
[BTZ black holes and scaling].
@ Warp drive: Alcubierre CQG(94)gq/00;
Pfenning & Ford CQG(97)gq [unphysical];
Coule CQG(98);
Low CQG(99)
[need for exotic matter]; Clark et al CQG(99)gq [null
geodesics]; González-Díaz
PRD(00)gq/99 [stability];
Van Den Broeck CQG(99)gq;
Loup et al gq/01, gq/02;
Hart et al gq/02 [hazards];
White GRG(03)
[mechanism]; Lobo & Visser CQG(04)gq [limitations],
gq/04-in
[linearization, energy]; Ellis gq/04 [and
antigravity]; González-Díaz PLB(07)
[superluminal]; Obousy & Cleaver JBIS-a0712
[and extra dimensions]; Finazzi et al PRD(09)-a0907 [semiclassical instability]; > s.a. quantum
field theory effects [negative
energy].
@ Production in experiments: Mironov et al in(06)-a0710,
Aref'eva & Volovich IJGMP(08)-a0710
[LHC].
@ Other examples: González-Díaz PRD(98)gq/97 [quantum];
DeDeo & Gott
PRD(02)
[2+1 Anti-de Sitter]; Charette et al JGP(03)m.DG/02 [closed
timelike curves
in flat
3D]; Ori PRL(05)gq [compact
vacuum core], PRD(07)gq
[development from regular initial surface].
In Quantum Mechanics > s.a. collapse; hidden
variables; locality; measurements [non-local];
quantum computation; quantum
effects.
@ Superluminal communication: Michalski qp/99-wd;
Kuzmich et al PRL(01)
[and quantum noise]; Yang qp/01;
Griffiths PRA(02)qp [no
problem]; Ferrero et al PRA(04)
[and non-linearity]; Malikotsinas qp/04 [and
entanglement]; Ferrero et al IJQI(05)qp [and
non-linear evolution]; Pankovic et al qp/05 [Griffiths'
bug shadow]; Bassi & Ghirardi IJTP(08)-a0711 [not
possible with wave-function collapse].
@ Superluminal tunneling: Aharonov et al PRL(98)qp [and
unstable states]; Chiao qp/98;
Ghose & Samal
PRE(01)qp/00 [and
special relativity]; Muga et al qp/02 [Hartman
effect]; Sokolovski PRS(04)qp/03;
> s.a. tunneling.
@ Causality violations: Bennett PRA(87), PRA(87)
[evidence in Compton scattering]; Valentini PRL(88);
Vaidman
FP(91);
Gray qp/98-wd
[time machine]; Greenberger & Svozil in(02)qp/05 [beam-splitter
model, paradox resolution], comment Wykes qp/05;
Pegg qp/05-in
[and self-consistency]; Svetlichny a0902 [effective
time travel]; > s.a. experiments [superluminal].
@ And unitarity: Anderson PRD(95)gq/94; Antonsen & Bormann IJTP(98)qp;
Everett PRD(04)gq [many-worlds];
Cornalba & Costa PRD(06).
@ Quantum mechanics with closed timelike curves: Hartle PRD(94)gq/93 [and
unitarity]; Fewster & Wells PRD(95)ht/94;
Politzer PRD(94)gq;
Rosenberg PRD(98)ht/97;
Brun et al PRL(09)-a0811
[state distinguishability, cryptography]; DeJonghe et al a0908 [discontinuous
evolution].
In Quantum Fueld Theory > s.a. quantum
field theory in curved backgrounds; modified
QED; violations
of lorentz symmetry.
* Motivation: QED vacua,
for example, become dispersive media under the influence of external conditions
(background fields, curvature, non-trivial
boundary
conditions, finite temperature), and may produce superluminal effects.twt
* Modeling: Microcausality
violations can be modeled by fields which do not commute at spacelike-related
points, non-commutative field theory.
* 2001: In curved
spacetime, whether there can actually be causality violation (vfront > c)
remains an open question.
@ Superluminal photon in
curved spacetime: Khriplovich PLB(95);
Daniels & Shore
PLB(96);
Dolgov & Novikov PLB(98)gq;
Konstantinov gq/98;
Shore gq/03-in,
CP(03)gq;
Hollowood & Shore PLB(07)-a0707,
NPB(08)-a0707 [QED].
@ Other topics: Hawking PRD(95)gq [loss
of quantum coherence]; Jain & Joglekar IJMPA(04)ht/03 [non-local 
4];
Nielsen & Ninomiya a0802 [at
the
LHC]; Dubovsky & Sibiryakov JHEP(08)-a0806 [in
2D quantum field theory with broken parity]; Kobakhidze a0811 [and
cmb anisotropy].
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21 sep 2009