Physics:Quantum Doubly special relativity: Difference between revisions

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{{Short description|Generalization of special relativity}}
{{Short description|Generalization of special relativity}}
 
{{Quantum book backlink|Advanced and frontier topics}}
{{Quantum book backlink|Advanced and frontier topics}}
 
{{Quantum article nav|previous=Physics:Quantum De Sitter invariant special relativity|previous label=De Sitter invariant special relativity|next=Physics:Quantum arithmetic geometry|next label=Arithmetic geometry}}
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'''Doubly special relativity'''<ref>{{cite book|first=Giovanni|last=Amelino-Camelia|date=1 November 2009|arxiv=1003.3942|volume=9|pages=123–170|doi=10.1142/9789814287333_0006|chapter=Doubly-Special Relativity: Facts, Myths and Some Key Open Issues|title = Recent Developments in Theoretical Physics|series = Statistical Science and Interdisciplinary Research|isbn = 978-981-4287-32-6|s2cid=118855372}}</ref><ref>{{cite journal|title=Doubly Special Relativity|first=Giovanni|last=Amelino-Camelia|date=1 July 2002|journal=Nature|volume=418|issue=6893|pages=34–35|doi=10.1038/418034a|arxiv=gr-qc/0207049|bibcode=2002Natur.418...34A|pmid=12097897|s2cid=16844423}}</ref> ('''DSR''') – also called '''deformed special relativity''' – is a modified theory of [[Wikipedia:special relativity|special relativity]] in which there is not only an observer-independent maximum [[Wikipedia:velocity|velocity]] (the [[Wikipedia:speed of light|speed of light]]), but also an observer-independent maximum energy scale (the [[Wikipedia:Planck energy|Planck energy]]) and/or a minimum length scale (the [[Wikipedia:Planck length|Planck length]]).<ref>
'''Doubly special relativity'''<ref>{{cite book|first=Giovanni|last=Amelino-Camelia|date=1 November 2009|arxiv=1003.3942|volume=9|pages=123–170|doi=10.1142/9789814287333_0006|chapter=Doubly-Special Relativity: Facts, Myths and Some Key Open Issues|title = Recent Developments in Theoretical Physics|series = Statistical Science and Interdisciplinary Research|isbn = 978-981-4287-32-6|s2cid=118855372}}</ref><ref>{{cite journal|title=Doubly Special Relativity|first=Giovanni|last=Amelino-Camelia|date=1 July 2002|journal=Nature|volume=418|issue=6893|pages=34–35|doi=10.1038/418034a|arxiv=gr-qc/0207049|bibcode=2002Natur.418...34A|pmid=12097897|s2cid=16844423}}</ref> ('''DSR''') – also called '''deformed special relativity''' – is a modified theory of special relativity in which there is not only an observer-independent maximum velocity (the speed of light), but also an observer-independent maximum energy scale (the Planck energy) and/or a minimum length scale (the Planck length).<ref>
{{Cite journal |author=Amelino-Camelia |first=Giovanni |year=2010 |title=Doubly-Special Relativity: Facts, Myths and Some Key Open Issues |journal=Symmetry |volume=2 |issue=4 |pages=230–271 |arxiv=1003.3942 |bibcode=2010rdtp.book..123A |doi=10.3390/sym2010230 |doi-access=free}}</ref> This contrasts with other{{clarify|reason=Does the use of "other" here mean that doubly special relativity also is Lorentz-violating, or does it mean that it is the other theories that are Lorentz-violating? If it is the former, it would be good to clarify that doubly special relativity is indeed Lorentz-violating. If it is the latter, it would be better to remove the word "other", because it makes it seem like it may be Lorentz-violating.|date=February 2026}} [[Wikipedia:Lorentz violation|Lorentz-violating]] theories, such as the [[Wikipedia:Standard-Model Extension|Standard-Model Extension]], where [[Wikipedia:Lorentz invariance|Lorentz invariance]] is instead broken by the presence of a [[Wikipedia:preferred frame|preferred frame]]. The main motivation for this theory is that the Planck energy should be the scale where as yet unknown [[Wikipedia:quantum gravity|quantum gravity]] effects become important and, due to invariance of physical laws, this scale should remain fixed in all inertial frames.<ref name="Hossenfelder2006">
{{Cite journal |author=Amelino-Camelia |first=Giovanni |year=2010 |title=Doubly-Special Relativity: Facts, Myths and Some Key Open Issues |journal=Symmetry |volume=2 |issue=4 |pages=230–271 |arxiv=1003.3942 |bibcode=2010rdtp.book..123A |doi=10.3390/sym2010230 |doi-access=free}}</ref> This contrasts with other{{clarify|reason=Does the use of "other" here mean that doubly special relativity also is Lorentz-violating, or does it mean that it is the other theories that are Lorentz-violating? If it is the former, it would be good to clarify that doubly special relativity is indeed Lorentz-violating. If it is the latter, it would be better to remove the word "other", because it makes it seem like it may be Lorentz-violating.|date=February 2026}} Lorentz-violating theories, such as the Standard-Model Extension, where Lorentz invariance is instead broken by the presence of a preferred frame. The main motivation for this theory is that the Planck energy should be the scale where as yet unknown quantum gravity effects become important and, due to invariance of physical laws, this scale should remain fixed in all inertial frames.<ref name="Hossenfelder2006">
{{Cite journal
{{Cite journal
  |first=S. |last=Hossenfelder
  |first=S. |last=Hossenfelder
  |title=Interpretation of Quantum Field Theories with a Minimal Length Scale
  |title=Interpretation of Quantum Field Theories with a Minimal Length Scale
  |journal=[[Wikipedia:Physical Review D|Physical Review D]]
  |journal=Physical Review D
  |volume=73 |issue= 10|article-number= 105013|year=2006
  |volume=73 |issue= 10|article-number= 105013|year=2006
  |arxiv=hep-th/0603032
  |arxiv=hep-th/0603032
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==History==
==History==
First attempts to modify special relativity by introducing an observer-independent length were made by Pavlopoulos (1967), who estimated this length at about {{val||e=-15|u=[[Wikipedia:metre|metre]]s}}.<ref>{{Cite journal |author=Pavlopoulos, T. G. |title=Breakdown of Lorentz Invariance |journal=Physical Review |volume=159 |issue=5 |pages=1106–1110 |year=1967 |doi=10.1103/PhysRev.159.1106 |bibcode=1967PhRv..159.1106P}}</ref><ref>{{Cite journal |author=Pavlopoulos, T. G. |title=Are we observing Lorentz violation in gamma ray bursts? |journal=Physics Letters B |volume=625 |issue=1–2 |pages=13–18 |year=2005 |doi=10.1016/j.physletb.2005.08.064 |bibcode=2005PhLB..625...13P|arxiv=astro-ph/0508294|s2cid=609286 }}</ref> In the context of [[Wikipedia:quantum gravity|quantum gravity]], [[Wikipedia:Giovanni Amelino-Camelia|Giovanni Amelino-Camelia]] (2000) introduced what is now called doubly special relativity, by proposing a specific realization of preserving invariance of the [[Wikipedia:Planck length|Planck length]] {{val|1.616255|e=-35|u=m}}.<ref>{{Cite journal |author=Amelino-Camelia |first=Giovanni |year=2001 |title=Testable scenario for relativity with minimum length |journal=Physics Letters B |volume=510 |issue=1–4 |pages=255–263 |arxiv=hep-th/0012238 |bibcode=2001PhLB..510..255A |doi=10.1016/S0370-2693(01)00506-8 |s2cid=119447462}}</ref><ref>{{Cite journal |author=Amelino-Camelia |first=Giovanni |year=2002 |title=Relativity in spacetimes with short-distance structure governed by an observer-independent (Planckian) length scale |journal=International Journal of Modern Physics D |volume=11 |issue=1 |pages=35–59 |arxiv=gr-qc/0012051 |bibcode=2002IJMPD..11...35A |doi=10.1142/S0218271802001330 |s2cid=16161466}}</ref> This was reformulated by Kowalski-Glikman (2001) in terms of an observer-independent [[Wikipedia:Planck mass|Planck mass]].<ref>{{Cite journal |author=Kowalski-Glikman, J.  |title=Observer-independent quantum of mass |journal=Physics Letters A |volume=286 |issue=6 |pages=391–394 |year=2001 |arxiv=hep-th/0102098 |doi=10.1016/S0375-9601(01)00465-0|bibcode = 2001PhLA..286..391K |s2cid=118984500 }}</ref> A different model, inspired by that of Amelino-Camelia, was proposed in 2001 by [[Wikipedia:João Magueijo|João Magueijo]] and [[Wikipedia:Lee Smolin|Lee Smolin]], who also focused on the invariance of [[Wikipedia:Planck energy|Planck energy]].<ref>{{Cite journal |last1=Magueijo |first1=J. |last2=Smolin |first2=L. |year=2002 |title=Lorentz invariance with an invariant energy scale |journal=Physical Review Letters |volume=88 |issue=19 |article-number=190403 |arxiv=hep-th/0112090 |bibcode=2002PhRvL..88s0403M |doi=10.1103/PhysRevLett.88.190403 |pmid=12005620 |s2cid=14468105}}</ref><ref>{{Cite journal |last1=Magueijo |first1=J. |last2=Smolin |first2=L. |year=2003 |title=Generalized Lorentz invariance with an invariant energy scale |journal=Physical Review D |volume=67 |issue=4 |article-number=044017 |arxiv=gr-qc/0207085 |bibcode=2003PhRvD..67d4017M |doi=10.1103/PhysRevD.67.044017 |s2cid=16998340}}</ref>
First attempts to modify special relativity by introducing an observer-independent length were made by Pavlopoulos (1967), who estimated this length at about {{val||e=-15|u=metres}}.<ref>{{Cite journal |author=Pavlopoulos, T. G. |title=Breakdown of Lorentz Invariance |journal=Physical Review |volume=159 |issue=5 |pages=1106–1110 |year=1967 |doi=10.1103/PhysRev.159.1106 |bibcode=1967PhRv..159.1106P}}</ref><ref>{{Cite journal |author=Pavlopoulos, T. G. |title=Are we observing Lorentz violation in gamma ray bursts? |journal=Physics Letters B |volume=625 |issue=1–2 |pages=13–18 |year=2005 |doi=10.1016/j.physletb.2005.08.064 |bibcode=2005PhLB..625...13P|arxiv=astro-ph/0508294|s2cid=609286 }}</ref> In the context of quantum gravity, Giovanni Amelino-Camelia (2000) introduced what is now called doubly special relativity, by proposing a specific realization of preserving invariance of the Planck length {{val|1.616255|e=-35|u=m}}.<ref>{{Cite journal |author=Amelino-Camelia |first=Giovanni |year=2001 |title=Testable scenario for relativity with minimum length |journal=Physics Letters B |volume=510 |issue=1–4 |pages=255–263 |arxiv=hep-th/0012238 |bibcode=2001PhLB..510..255A |doi=10.1016/S0370-2693(01)00506-8 |s2cid=119447462}}</ref><ref>{{Cite journal |author=Amelino-Camelia |first=Giovanni |year=2002 |title=Relativity in spacetimes with short-distance structure governed by an observer-independent (Planckian) length scale |journal=International Journal of Modern Physics D |volume=11 |issue=1 |pages=35–59 |arxiv=gr-qc/0012051 |bibcode=2002IJMPD..11...35A |doi=10.1142/S0218271802001330 |s2cid=16161466}}</ref> This was reformulated by Kowalski-Glikman (2001) in terms of an observer-independent Planck mass.<ref>{{Cite journal |author=Kowalski-Glikman, J.  |title=Observer-independent quantum of mass |journal=Physics Letters A |volume=286 |issue=6 |pages=391–394 |year=2001 |arxiv=hep-th/0102098 |doi=10.1016/S0375-9601(01)00465-0|bibcode = 2001PhLA..286..391K |s2cid=118984500 }}</ref> A different model, inspired by that of Amelino-Camelia, was proposed in 2001 by João Magueijo and Lee Smolin, who also focused on the invariance of Planck energy.<ref>{{Cite journal |last1=Magueijo |first1=J. |last2=Smolin |first2=L. |year=2002 |title=Lorentz invariance with an invariant energy scale |journal=Physical Review Letters |volume=88 |issue=19 |article-number=190403 |arxiv=hep-th/0112090 |bibcode=2002PhRvL..88s0403M |doi=10.1103/PhysRevLett.88.190403 |pmid=12005620 |s2cid=14468105}}</ref><ref>{{Cite journal |last1=Magueijo |first1=J. |last2=Smolin |first2=L. |year=2003 |title=Generalized Lorentz invariance with an invariant energy scale |journal=Physical Review D |volume=67 |issue=4 |article-number=044017 |arxiv=gr-qc/0207085 |bibcode=2003PhRvD..67d4017M |doi=10.1103/PhysRevD.67.044017 |s2cid=16998340}}</ref>


It was realized that there are, indeed, three kinds of deformation of special relativity that allow one to achieve an invariance of the Planck energy; either as a maximum energy, as a maximal momentum, or both. DSR models are possibly related to [[Wikipedia:loop quantum gravity|loop quantum gravity]] in 2+1 dimensions (two space, one time), and it has been conjectured that a relation also exists in 3+1 dimensions.<ref>{{Cite journal |author1=Amelino-Camelia, Giovanni |author2=Smolin, Lee |author3=Starodubtsev, Artem |title=Quantum symmetry, the cosmological constant and Planck-scale phenomenology |journal=Classical and Quantum Gravity |volume=21 |issue=13 |pages=3095–3110 |year=2004 |arxiv=hep-th/0306134 |doi=10.1088/0264-9381/21/13/002|bibcode = 2004CQGra..21.3095A |s2cid=15024104 }}</ref><ref>{{Cite journal |author1=Freidel, Laurent |author2=Kowalski-Glikman, Jerzy |author3=Smolin, Lee |title=2+1 gravity and doubly special relativity |journal=Physical Review D |volume=69 |issue=4 |article-number=044001 |year=2004 |arxiv=hep-th/0307085 |doi=10.1103/PhysRevD.69.044001|bibcode = 2004PhRvD..69d4001F |s2cid=119509057 }}</ref>
It was realized that there are, indeed, three kinds of deformation of special relativity that allow one to achieve an invariance of the Planck energy; either as a maximum energy, as a maximal momentum, or both. DSR models are possibly related to loop quantum gravity in 2+1 dimensions (two space, one time), and it has been conjectured that a relation also exists in 3+1 dimensions.<ref>{{Cite journal |author1=Amelino-Camelia, Giovanni |author2=Smolin, Lee |author3=Starodubtsev, Artem |title=Quantum symmetry, the cosmological constant and Planck-scale phenomenology |journal=Classical and Quantum Gravity |volume=21 |issue=13 |pages=3095–3110 |year=2004 |arxiv=hep-th/0306134 |doi=10.1088/0264-9381/21/13/002|bibcode = 2004CQGra..21.3095A |s2cid=15024104 }}</ref><ref>{{Cite journal |author1=Freidel, Laurent |author2=Kowalski-Glikman, Jerzy |author3=Smolin, Lee |title=2+1 gravity and doubly special relativity |journal=Physical Review D |volume=69 |issue=4 |article-number=044001 |year=2004 |arxiv=hep-th/0307085 |doi=10.1103/PhysRevD.69.044001|bibcode = 2004PhRvD..69d4001F |s2cid=119509057 }}</ref>


The motivation for these proposals is mainly theoretical, based on the following observation: The Planck energy is expected to play a fundamental role in a theory of [[Wikipedia:quantum gravity|quantum gravity]]; setting the scale at which quantum gravity effects cannot be neglected and new phenomena might become important. If special relativity is to hold up exactly to this scale, different observers would observe quantum gravity effects at different scales, due to the [[Wikipedia:Lorentz–FitzGerald contraction|Lorentz–FitzGerald contraction]], in contradiction to the principle that all inertial observers should be able to describe phenomena by the same physical laws. This motivation has been criticized, on the grounds that the result of a Lorentz transformation does not itself constitute an observable phenomenon.<ref name="Hossenfelder2006"/> DSR also suffers from several inconsistencies in formulation that have yet to be resolved.<ref name="Aloisio2004">
The motivation for these proposals is mainly theoretical, based on the following observation: The Planck energy is expected to play a fundamental role in a theory of quantum gravity; setting the scale at which quantum gravity effects cannot be neglected and new phenomena might become important. If special relativity is to hold up exactly to this scale, different observers would observe quantum gravity effects at different scales, due to the Lorentz–FitzGerald contraction, in contradiction to the principle that all inertial observers should be able to describe phenomena by the same physical laws. This motivation has been criticized, on the grounds that the result of a Lorentz transformation does not itself constitute an observable phenomenon.<ref name="Hossenfelder2006"/> DSR also suffers from several inconsistencies in formulation that have yet to be resolved.<ref name="Aloisio2004">
{{Cite journal |last1=Aloisio |first1=R. |last2=Galante |first2=A. |last3=Grillo |first3=A. F. |last4=Luzio |first4=E. |last5=Mendez |first5=F. |year=2004 |title=Approaching Space Time Through Velocity in Doubly Special Relativity |journal=[[Wikipedia:Physical Review D|Physical Review D]] |volume=70 |issue=12 |article-number=125012 |arxiv=gr-qc/0410020 |bibcode=2004PhRvD..70l5012A |doi=10.1103/PhysRevD.70.125012 |s2cid=2111595}}</ref><ref name="Aloisio2005">
{{Cite journal |last1=Aloisio |first1=R. |last2=Galante |first2=A. |last3=Grillo |first3=A. F. |last4=Luzio |first4=E. |last5=Mendez |first5=F. |year=2004 |title=Approaching Space Time Through Velocity in Doubly Special Relativity |journal=Physical Review D |volume=70 |issue=12 |article-number=125012 |arxiv=gr-qc/0410020 |bibcode=2004PhRvD..70l5012A |doi=10.1103/PhysRevD.70.125012 |s2cid=2111595}}</ref><ref name="Aloisio2005">
{{Cite journal
{{Cite journal
  |first1=R. |last1=Aloisio |first2=A. |last2=Galante |first3=A.F. |last3=Grillo
  |first1=R. |last1=Aloisio |first2=A. |last2=Galante |first3=A.F. |last3=Grillo
  |first4=E. |last4=Luzio |first5=F. |last5=Mendez
  |first4=E. |last4=Luzio |first5=F. |last5=Mendez
  |title=A note on DSR-like approach to space-time
  |title=A note on DSR-like approach to space-time
  |journal=[[Wikipedia:Physics Letters B|Physics Letters B]]
  |journal=Physics Letters B
  |volume=610 |issue= 1–2|pages=101–106
  |volume=610 |issue= 1–2|pages=101–106
  |year=2005
  |year=2005
  |arxiv=gr-qc/0501079
  |arxiv=gr-qc/0501079
  |doi=10.1016/j.physletb.2005.01.090
  |doi=10.1016/j.physletb.2005.01.090
|bibcode = 2005PhLB..610..101A |s2cid=119346228 }}</ref> Most notably, it is difficult to recover the standard transformation behavior for macroscopic bodies, known as the soccer ball problem.<ref>{{Cite journal |last=Hossenfelder |first=Sabine |author-link=Sabine Hossenfelder |date=9 July 2014 |title=The Soccer-Ball Problem |url=http://www.emis.de/journals/SIGMA/2014/074/ |journal=Symmetry, Integrability and Geometry: Methods and Applications |volume=10 |page=74 |arxiv=1403.2080 |bibcode=2014SIGMA..10..074H |doi=10.3842/SIGMA.2014.074 |s2cid=14373748 |access-date=16 April 2022 |archive-date=19 March 2022 |archive-url=https://web.archive.org/web/20220319004139/https://www.emis.de/journals/SIGMA/2014/074/ |url-status=live }}</ref> The other conceptual difficulty is that DSR is ''[[Wikipedia:a priori|a priori]]'' formulated in [[Wikipedia:momentum space|momentum space]]. There is, as of yet, no consistent formulation of the model in [[Wikipedia:position space|position space]].
|bibcode = 2005PhLB..610..101A |s2cid=119346228 }}</ref> Most notably, it is difficult to recover the standard transformation behavior for macroscopic bodies, known as the soccer ball problem.<ref>{{Cite journal |last=Hossenfelder |first=Sabine |author-link=Sabine Hossenfelder |date=9 July 2014 |title=The Soccer-Ball Problem |url=http://www.emis.de/journals/SIGMA/2014/074/ |journal=Symmetry, Integrability and Geometry: Methods and Applications |volume=10 |page=74 |arxiv=1403.2080 |bibcode=2014SIGMA..10..074H |doi=10.3842/SIGMA.2014.074 |s2cid=14373748 |access-date=16 April 2022 |archive-date=19 March 2022 |archive-url=https://web.archive.org/web/20220319004139/https://www.emis.de/journals/SIGMA/2014/074/ |url-status=live }}</ref> The other conceptual difficulty is that DSR is ''a priori'' formulated in momentum space. There is, as of yet, no consistent formulation of the model in position space.


==Predictions==
==Predictions==
{{see also|Physics:Modern searches for Lorentz violation}}
''Related topic:'' Modern searches for Lorentz violation
[[File:GRB080319B illustration NASA.jpg|thumb|Measurements on light from gamma-ray bursts show that the speed of light does not vary with energy. Artist's conception.]]
[[File:GRB080319B illustration NASA.jpg|thumb|Measurements on light from gamma-ray bursts show that the speed of light does not vary with energy. Artist's conception.]]
Experiments to date have not observed contradictions to Special Relativity.
Experiments to date have not observed contradictions to Special Relativity.


It was initially speculated that ordinary special relativity and doubly special relativity would make distinct physical predictions in high-energy processes and, in particular, the derivation of the [[Wikipedia:Greisen–Zatsepin–Kuzmin limit|GZK limit]] on energies of [[Wikipedia:cosmic ray|cosmic rays]] from distant sources would not be valid. However, it is now established that standard doubly special relativity does not predict any suppression of the GZK cutoff, contrary to the models where an [[Wikipedia:preferred frame|absolute local rest frame]] exists, such as [[Wikipedia:effective field theory|effective field theories]] like the [[Wikipedia:Standard-Model Extension|Standard-Model Extension]].
It was initially speculated that ordinary special relativity and doubly special relativity would make distinct physical predictions in high-energy processes and, in particular, the derivation of the GZK limit on energies of cosmic rays from distant sources would not be valid. However, it is now established that standard doubly special relativity does not predict any suppression of the GZK cutoff, contrary to the models where an absolute local rest frame exists, such as effective field theories like the Standard-Model Extension.


Since DSR generically (though not necessarily) implies an energy-dependence of the speed of light, it has further been predicted that, if there are modifications to first order in energy over the Planck mass, this energy-dependence would be observable in high energetic [[Wikipedia:photon|photons]] reaching Earth from distant [[Wikipedia:gamma ray burst|gamma ray bursts]]. Depending on whether the now energy-dependent speed of light increases or decreases with energy (a model-dependent feature), highly energetic photons would be faster or slower than the lower energetic ones.<ref name="Smolin2009">
Since DSR generically (though not necessarily) implies an energy-dependence of the speed of light, it has further been predicted that, if there are modifications to first order in energy over the Planck mass, this energy-dependence would be observable in high energetic photons reaching Earth from distant gamma ray bursts. Depending on whether the now energy-dependent speed of light increases or decreases with energy (a model-dependent feature), highly energetic photons would be faster or slower than the lower energetic ones.<ref name="Smolin2009">
{{Cite journal |last1=Amelino-Camelia |first1=Giovanni |last2=Smolin |first2=Lee |year=2009 |title=Prospects for constraining quantum gravity dispersion with near term observations |journal=[[Wikipedia:Physical Review D|Physical Review D]] |volume=80 |issue=8 |article-number=084017 |arxiv=0906.3731 |bibcode=2009PhRvD..80h4017A |doi=10.1103/PhysRevD.80.084017 |s2cid=9533538}}</ref> However, the [[Wikipedia:Fermi Gamma-ray Space Telescope|Fermi-LAT]] experiment in 2009 measured a 31&nbsp;GeV photon, which nearly simultaneously arrived with other photons from the same burst, which excluded such dispersion effects even above the Planck energy.<ref name=lat>{{cite journal |author=Fermi LAT Collaboration|title=A limit on the variation of the speed of light arising from quantum gravity effects|journal=Nature|volume=462|issue=7271 |year=2009|pages=331–334|doi=10.1038/nature08574|arxiv=0908.1832|pmid=19865083
{{Cite journal |last1=Amelino-Camelia |first1=Giovanni |last2=Smolin |first2=Lee |year=2009 |title=Prospects for constraining quantum gravity dispersion with near term observations |journal=Physical Review D |volume=80 |issue=8 |article-number=084017 |arxiv=0906.3731 |bibcode=2009PhRvD..80h4017A |doi=10.1103/PhysRevD.80.084017 |s2cid=9533538}}</ref> However, the Fermi-LAT experiment in 2009 measured a 31&nbsp;GeV photon, which nearly simultaneously arrived with other photons from the same burst, which excluded such dispersion effects even above the Planck energy.<ref name=lat>{{cite journal |author=Fermi LAT Collaboration|title=A limit on the variation of the speed of light arising from quantum gravity effects|journal=Nature|volume=462|issue=7271 |year=2009|pages=331–334|doi=10.1038/nature08574|arxiv=0908.1832|pmid=19865083
|bibcode = 2009Natur.462..331A |s2cid=205218977}}</ref> Moreover, it has been argued that DSR, with an energy-dependent speed of light, is inconsistent and first order effects are ruled out already because they would lead to non-local particle interactions that would long have been observed in particle physics experiments.<ref name="Hossenfelder2009">
|bibcode = 2009Natur.462..331A |s2cid=205218977}}</ref> Moreover, it has been argued that DSR, with an energy-dependent speed of light, is inconsistent and first order effects are ruled out already because they would lead to non-local particle interactions that would long have been observed in particle physics experiments.<ref name="Hossenfelder2009">
{{cite arXiv
{{cite arXiv
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==Further reading==
==Further reading==
*{{Cite journal |last=Amelino-Camelia |first=Giovanni |title=Doubly-Special Relativity: First Results and Key Open Problems |journal=[[Wikipedia:International Journal of Modern Physics D|International Journal of Modern Physics D]] |volume=11 |issue=10 |pages=1643&ndash;1669 |year=2002 |doi=10.1142/S021827180200302X |arxiv=gr-qc/0210063 |bibcode=2002IJMPD..11.1643A |s2cid=43004370}}
*{{Cite journal |last=Amelino-Camelia |first=Giovanni |title=Doubly-Special Relativity: First Results and Key Open Problems |journal=International Journal of Modern Physics D |volume=11 |issue=10 |pages=1643&ndash;1669 |year=2002 |doi=10.1142/S021827180200302X |arxiv=gr-qc/0210063 |bibcode=2002IJMPD..11.1643A |s2cid=43004370}}
*{{Cite journal |last=Amelino-Camelia |first=Giovanni |title=Relativity: Special treatment |journal=[[Wikipedia:Nature (journal)|Nature]] |volume=418 |issue=6893 |pages=34–35 |year=2002 |doi=10.1038/418034a |pmid=12097897 |arxiv=gr-qc/0207049 |bibcode=2002Natur.418...34A |s2cid=16844423}}
*{{Cite journal |last=Amelino-Camelia |first=Giovanni |title=Relativity: Special treatment |journal=Nature |volume=418 |issue=6893 |pages=34–35 |year=2002 |doi=10.1038/418034a |pmid=12097897 |arxiv=gr-qc/0207049 |bibcode=2002Natur.418...34A |s2cid=16844423}}
*{{Cite book
*{{Cite book
  |last=Cardone |first=F. |author-link=Fabio Cardone
  |last=Cardone |first=F. |author-link=Fabio Cardone
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  |title=Energy and Geometry: An Introduction to Deformed Special Relativity
  |title=Energy and Geometry: An Introduction to Deformed Special Relativity
  |year=2004
  |year=2004
  |publisher=[[Wikipedia:World Scientific|World Scientific]]
  |publisher=World Scientific
  |isbn=981-238-728-5
  |isbn=981-238-728-5
}}
}}
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  |arxiv=hep-th/0405273 |doi=10.1007/b105189
  |arxiv=hep-th/0405273 |doi=10.1007/b105189
}}
}}
*{{Cite book |title=[[Wikipedia:The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next|The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next]] |last=Smolin, Lee |author-link=Lee Smolin |year=2006 |publisher=Houghton Mifflin |location=Boston, Massachusetts |isbn=978-0-618-55105-7 |oclc=64453453 |chapter=Chapter 14. Building on Einstein}}<!--|access-date=19 August 2010--> Smolin writes for the layman a brief history of the development of DSR and how it ties in with [[Wikipedia:string theory|string theory]] and [[Wikipedia:cosmology|cosmology]].
*{{Cite book |title=The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next |last=Smolin, Lee |author-link=Lee Smolin |year=2006 |publisher=Houghton Mifflin |location=Boston, Massachusetts |isbn=978-0-618-55105-7 |oclc=64453453 |chapter=Chapter 14. Building on Einstein}}<!--|access-date=19 August 2010--> Smolin writes for the layman a brief history of the development of DSR and how it ties in with string theory and cosmology.
=See also=
=See also=
{{#invoke:PhysicsQC|tocHeadingAndList|Physics:Quantum basics/See also}}
{{#invoke:PhysicsQC|tocHeadingAndList|Physics:Quantum basics/See also}}

Latest revision as of 11:34, 22 May 2026

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Doubly special relativity[1][2] (DSR) – also called deformed special relativity – is a modified theory of special relativity in which there is not only an observer-independent maximum velocity (the speed of light), but also an observer-independent maximum energy scale (the Planck energy) and/or a minimum length scale (the Planck length).[3] This contrasts with other[clarification needed] Lorentz-violating theories, such as the Standard-Model Extension, where Lorentz invariance is instead broken by the presence of a preferred frame. The main motivation for this theory is that the Planck energy should be the scale where as yet unknown quantum gravity effects become important and, due to invariance of physical laws, this scale should remain fixed in all inertial frames.[4]

Quantum Doubly special relativity.

History

First attempts to modify special relativity by introducing an observer-independent length were made by Pavlopoulos (1967), who estimated this length at about 10−15 m.[5][6] In the context of quantum gravity, Giovanni Amelino-Camelia (2000) introduced what is now called doubly special relativity, by proposing a specific realization of preserving invariance of the Planck length 1.616255×10−35 m.[7][8] This was reformulated by Kowalski-Glikman (2001) in terms of an observer-independent Planck mass.[9] A different model, inspired by that of Amelino-Camelia, was proposed in 2001 by João Magueijo and Lee Smolin, who also focused on the invariance of Planck energy.[10][11]

It was realized that there are, indeed, three kinds of deformation of special relativity that allow one to achieve an invariance of the Planck energy; either as a maximum energy, as a maximal momentum, or both. DSR models are possibly related to loop quantum gravity in 2+1 dimensions (two space, one time), and it has been conjectured that a relation also exists in 3+1 dimensions.[12][13]

The motivation for these proposals is mainly theoretical, based on the following observation: The Planck energy is expected to play a fundamental role in a theory of quantum gravity; setting the scale at which quantum gravity effects cannot be neglected and new phenomena might become important. If special relativity is to hold up exactly to this scale, different observers would observe quantum gravity effects at different scales, due to the Lorentz–FitzGerald contraction, in contradiction to the principle that all inertial observers should be able to describe phenomena by the same physical laws. This motivation has been criticized, on the grounds that the result of a Lorentz transformation does not itself constitute an observable phenomenon.[4] DSR also suffers from several inconsistencies in formulation that have yet to be resolved.[14][15] Most notably, it is difficult to recover the standard transformation behavior for macroscopic bodies, known as the soccer ball problem.[16] The other conceptual difficulty is that DSR is a priori formulated in momentum space. There is, as of yet, no consistent formulation of the model in position space.

Predictions

Related topic: Modern searches for Lorentz violation

Measurements on light from gamma-ray bursts show that the speed of light does not vary with energy. Artist's conception.

Experiments to date have not observed contradictions to Special Relativity.

It was initially speculated that ordinary special relativity and doubly special relativity would make distinct physical predictions in high-energy processes and, in particular, the derivation of the GZK limit on energies of cosmic rays from distant sources would not be valid. However, it is now established that standard doubly special relativity does not predict any suppression of the GZK cutoff, contrary to the models where an absolute local rest frame exists, such as effective field theories like the Standard-Model Extension.

Since DSR generically (though not necessarily) implies an energy-dependence of the speed of light, it has further been predicted that, if there are modifications to first order in energy over the Planck mass, this energy-dependence would be observable in high energetic photons reaching Earth from distant gamma ray bursts. Depending on whether the now energy-dependent speed of light increases or decreases with energy (a model-dependent feature), highly energetic photons would be faster or slower than the lower energetic ones.[17] However, the Fermi-LAT experiment in 2009 measured a 31 GeV photon, which nearly simultaneously arrived with other photons from the same burst, which excluded such dispersion effects even above the Planck energy.[18] Moreover, it has been argued that DSR, with an energy-dependent speed of light, is inconsistent and first order effects are ruled out already because they would lead to non-local particle interactions that would long have been observed in particle physics experiments.[19]

De Sitter relativity

Since the de Sitter group naturally incorporates an invariant length parameter, de Sitter relativity can be interpreted as an example of doubly special relativity because de Sitter spacetime incorporates invariant velocity, as well as length parameter. There is a fundamental difference, though: whereas in all doubly special relativity models the Lorentz symmetry is violated, in de Sitter relativity it remains as a physical symmetry. A drawback of the usual doubly special relativity models is that they are valid only at the energy scales where ordinary special relativity is supposed to break down, giving rise to a patchwork relativity. On the other hand, de Sitter relativity is found to be invariant under a simultaneous re-scaling of mass, energy and momentum, and is consequently valid at all energy scales.

Further reading

  • Amelino-Camelia, Giovanni (2002). "Doubly-Special Relativity: First Results and Key Open Problems". International Journal of Modern Physics D 11 (10): 1643–1669. doi:10.1142/S021827180200302X. Bibcode: 2002IJMPD..11.1643A. 
  • Amelino-Camelia, Giovanni (2002). "Relativity: Special treatment". Nature 418 (6893): 34–35. doi:10.1038/418034a. PMID 12097897. Bibcode: 2002Natur.418...34A. 
  • Cardone, F.; Mignani, R. (2004). Energy and Geometry: An Introduction to Deformed Special Relativity. World Scientific. ISBN 981-238-728-5. 
  • Jafari, N.; Shariati, A. (2006). "Doubly Special Relativity: A New Relativity or Not?". 841. pp. 462–465. doi:10.1063/1.2218214. 
  • Kowalski-Glikman, J. (2005). "Introduction to Doubly Special Relativity". Planck Scale Effects in Astrophysics and Cosmology. Lecture Notes in Physics. 669. pp. 131–159. doi:10.1007/b105189. ISBN 978-3-540-25263-4. 
  • Smolin, Lee (2006). "Chapter 14. Building on Einstein". The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next. Boston, Massachusetts: Houghton Mifflin. ISBN 978-0-618-55105-7. OCLC 64453453.  Smolin writes for the layman a brief history of the development of DSR and how it ties in with string theory and cosmology.

See also

Table of contents (217 articles)

Index

Full contents

References

  1. Amelino-Camelia, Giovanni (1 November 2009). "Doubly-Special Relativity: Facts, Myths and Some Key Open Issues". Recent Developments in Theoretical Physics. Statistical Science and Interdisciplinary Research. 9. pp. 123–170. doi:10.1142/9789814287333_0006. ISBN 978-981-4287-32-6. 
  2. Amelino-Camelia, Giovanni (1 July 2002). "Doubly Special Relativity". Nature 418 (6893): 34–35. doi:10.1038/418034a. PMID 12097897. Bibcode: 2002Natur.418...34A. 
  3. Amelino-Camelia, Giovanni (2010). "Doubly-Special Relativity: Facts, Myths and Some Key Open Issues". Symmetry 2 (4): 230–271. doi:10.3390/sym2010230. Bibcode: 2010rdtp.book..123A. 
  4. 4.0 4.1 Hossenfelder, S. (2006). "Interpretation of Quantum Field Theories with a Minimal Length Scale". Physical Review D 73 (10). doi:10.1103/PhysRevD.73.105013. Bibcode: 2006PhRvD..73j5013H. 
  5. Pavlopoulos, T. G. (1967). "Breakdown of Lorentz Invariance". Physical Review 159 (5): 1106–1110. doi:10.1103/PhysRev.159.1106. Bibcode: 1967PhRv..159.1106P. 
  6. Pavlopoulos, T. G. (2005). "Are we observing Lorentz violation in gamma ray bursts?". Physics Letters B 625 (1–2): 13–18. doi:10.1016/j.physletb.2005.08.064. Bibcode: 2005PhLB..625...13P. 
  7. Amelino-Camelia, Giovanni (2001). "Testable scenario for relativity with minimum length". Physics Letters B 510 (1–4): 255–263. doi:10.1016/S0370-2693(01)00506-8. Bibcode: 2001PhLB..510..255A. 
  8. Amelino-Camelia, Giovanni (2002). "Relativity in spacetimes with short-distance structure governed by an observer-independent (Planckian) length scale". International Journal of Modern Physics D 11 (1): 35–59. doi:10.1142/S0218271802001330. Bibcode: 2002IJMPD..11...35A. 
  9. Kowalski-Glikman, J. (2001). "Observer-independent quantum of mass". Physics Letters A 286 (6): 391–394. doi:10.1016/S0375-9601(01)00465-0. Bibcode: 2001PhLA..286..391K. 
  10. Magueijo, J.; Smolin, L. (2002). "Lorentz invariance with an invariant energy scale". Physical Review Letters 88 (19). doi:10.1103/PhysRevLett.88.190403. PMID 12005620. Bibcode: 2002PhRvL..88s0403M. 
  11. Magueijo, J.; Smolin, L. (2003). "Generalized Lorentz invariance with an invariant energy scale". Physical Review D 67 (4). doi:10.1103/PhysRevD.67.044017. Bibcode: 2003PhRvD..67d4017M. 
  12. Amelino-Camelia, Giovanni; Smolin, Lee; Starodubtsev, Artem (2004). "Quantum symmetry, the cosmological constant and Planck-scale phenomenology". Classical and Quantum Gravity 21 (13): 3095–3110. doi:10.1088/0264-9381/21/13/002. Bibcode: 2004CQGra..21.3095A. 
  13. Freidel, Laurent; Kowalski-Glikman, Jerzy; Smolin, Lee (2004). "2+1 gravity and doubly special relativity". Physical Review D 69 (4). doi:10.1103/PhysRevD.69.044001. Bibcode: 2004PhRvD..69d4001F. 
  14. Aloisio, R.; Galante, A.; Grillo, A. F.; Luzio, E.; Mendez, F. (2004). "Approaching Space Time Through Velocity in Doubly Special Relativity". Physical Review D 70 (12). doi:10.1103/PhysRevD.70.125012. Bibcode: 2004PhRvD..70l5012A. 
  15. Aloisio, R.; Galante, A.; Grillo, A.F.; Luzio, E.; Mendez, F. (2005). "A note on DSR-like approach to space-time". Physics Letters B 610 (1–2): 101–106. doi:10.1016/j.physletb.2005.01.090. Bibcode: 2005PhLB..610..101A. 
  16. Hossenfelder, Sabine (9 July 2014). "The Soccer-Ball Problem". Symmetry, Integrability and Geometry: Methods and Applications 10: 74. doi:10.3842/SIGMA.2014.074. Bibcode: 2014SIGMA..10..074H. http://www.emis.de/journals/SIGMA/2014/074/. Retrieved 16 April 2022. 
  17. Amelino-Camelia, Giovanni; Smolin, Lee (2009). "Prospects for constraining quantum gravity dispersion with near term observations". Physical Review D 80 (8). doi:10.1103/PhysRevD.80.084017. Bibcode: 2009PhRvD..80h4017A. 
  18. Fermi LAT Collaboration (2009). "A limit on the variation of the speed of light arising from quantum gravity effects". Nature 462 (7271): 331–334. doi:10.1038/nature08574. PMID 19865083. Bibcode: 2009Natur.462..331A. 
  19. Hossenfelder, S. (2009). "The Box-Problem in Deformed Special Relativity". arXiv:0912.0090 [gr-qc].


Author: Harold Foppele


Source attribution: Physics:Quantum Doubly special relativity