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Open Problems

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Spectral Action in Noncommutative Geometry

Part of the book series: SpringerBriefs in Mathematical Physics ((BRIEFSMAPHY,volume 27))

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Abstract

As a desert, we serve a number of open problems connected with the subject matter of the book. Some of them consider the general framework of spectral triples and its possible extensions, while the other are more specific and relate to the properties of the spectral action. The problems are essentially of mathematical nature, though, at least in some cases, the conceptual skeleton strongly depends upon the input from physics. To our mind, the solution to each of these stumbling blocks would advance our understanding of the foundations and implications of the Spectral Action Principle. We therefore cordially invite the Reader to contemplate the list below, both from mathematical and physical perspectives.

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Notes

  1. 1.

    Such a fixed \(C^*\)-algebra can come from physics — as the natural algebra of observables of a given system (see e.g. [42, 49, 61]).

References

  1. Baer, C., Strohmaier, A.: An index theorem for Lorentzian manifolds with compact spacelike Cauchy boundary. Am. J. Math. 1, 1 (2017). (to appear)

    Google Scholar 

  2. Baum, H.: Spin-Strukturen und Dirac-Operatoren über pseudoriemannschen Mannigfaltig-keiten. Teubner-Texte zur Mathematik, vol. 41. Teubner, Leipzig (1981)

    MATH  Google Scholar 

  3. Beem, J., Ehrlich, P., Easley, K.: Global Lorentzian Geometry. Monographs and Textbooks in Pure and Applied Mathematics, vol. 202. CRC Press, Boca Raton (1996)

    MATH  Google Scholar 

  4. Bertozzini, P., Conti, R., Lewkeeratiyutkul, W.: Modular theory, non-commutative geometry and quantum gravity. SIGMA 6, 47p. (2010)

    MathSciNet  MATH  Google Scholar 

  5. Besnard, F., Nadir, B.: On the definition of spacetimes in noncommutative geometry: Part I. J. Geom. Phys. 123, 292–309 (2018). See also arXiv:1611.07842

    Article  ADS  MathSciNet  MATH  Google Scholar 

  6. Bognár, J.: Indefinite Inner Product Spaces. Springer, Berlin (1974)

    Book  MATH  Google Scholar 

  7. Boyd, J.P.: The Devil’s invention: asymptotics, superasymptotics and hyperasymptotic series. Acta Appl. Math. 56, 1–98 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  8. Brzeziński, T., Ciccoli, N., Dąbrowski, L., Sitarz, A.: Twisted reality condition for Dirac operators. Math. Phys. Anal. Geom. 19(3), 16 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  9. Carey, A.L., Gayral, V., Rennie, A., Sukochev, F.: Integration on locally compact noncommutative spaces. J. Funct. Anal. 263, 383–414 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  10. Carey, A.L., Gayral, V., Rennie, A., Sukochev, F.A.: Index Theory for Locally Compact Noncommutative Geometries. Memoirs of the AMS, vol. 231. American Mathematical Society, Providence (2014)

    Google Scholar 

  11. Carey, A.L., Neshveyev, S., Nest, R., Rennie, A.: Twisted cyclic theory, equivariant KK-theory and KMS states. Journal für die reine und angewandte Mathematik 650, 161–191 (2011)

    MathSciNet  MATH  Google Scholar 

  12. Carey, A.L., Phillips, J., Rennie, A.: Semifinite spectral triples associated with graph \(C^*\)-algebras. In: Albeverio, S., Marcolli, M., Paycha, S., Plazas, J. (eds.) Traces in Number Theory, Geometry and Quantum Fields, pp. 35–56. Vieweg, Wiesbaden (2008)

    Google Scholar 

  13. Chamseddine, A.H., Connes, A.: Scale invariance in the spectral action. J. Math. Phys. 47, 063504 (2006)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  14. Christensen, E., Ivan, C.: Spectral triples for AF \(C^*\)-algebras and metrics on the Cantor set. J. Oper. Theory 56, 17–46 (2006)

    Google Scholar 

  15. Connes, A., Landi, G.: Noncommutative manifolds, the instanton algebra and isospectral deformations. Commun. Math. Phys. 221(1), 141–159 (2001)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  16. Connes, A., Marcolli, M.: Noncommutative Geometry, Quantum Fields and Motives. Colloquium Publications, vol. 55. American Mathematical Society, Providence (2008)

    MATH  Google Scholar 

  17. Connes, A., Moscovici, H.: Type III and spectral triples. In: Albeverio, S., Marcolli, M., Paycha, S., Plazas, J. (eds.) Traces in Number Theory, Geometry and Quantum Fields, pp. 57–71. Vieweg, Wiesbaden (2008)

    Google Scholar 

  18. Connes, A., Moscovici, H.: Modular curvature for noncommutative two-tori. J. Am. Math. Soc. 27(3), 639–684 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  19. Connes, A., Tretkoff, P.: The Gauss-Bonnet theorem for the noncommutative two torus. In: Consani, C., Connes, A. (eds.) Noncommutative Geometry, Arithmetic and Related Topics, pp. 141–158. The Johns Hopkins University Press, Baltimore (2011)

    MATH  Google Scholar 

  20. D’Andrea, F., Kurkov, M.A., Lizzi, F.: Wick rotation and fermion doubling in noncommutative geometry. Phys. Rev. D 94, 025030 (2016)

    Article  ADS  MathSciNet  Google Scholar 

  21. Devastato, A., Farnsworth, S., Lizzi, F., Martinetti, P.: Lorentz signature and twisted spectral triples. J. High Energy Phys. 03(2018)089

    Google Scholar 

  22. Devastato, A., Martinetti, P.: Twisted spectral triple for the standard model and spontaneous breaking of the grand symmetry. Math. Phys. Anal. Geom. 20(2), 1–43 (2017)

    MathSciNet  MATH  Google Scholar 

  23. van den Dungen, K., Paschke, M., Rennie, A.: Pseudo-Riemannian spectral triples and the harmonic oscillator. J. Geom. Phys. 73, 37–55 (2013)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  24. van den Dungen, K., Rennie, A.: Indefinite Kasparov modules and pseudo-Riemannian manifolds. Ann. Henri Poincaré 17(11), 3255–3286 (2016)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  25. Eckstein, M.: The geometry of noncommutative spacetimes. Universe 3(1), 25 (2017)

    Article  ADS  Google Scholar 

  26. Eckstein, M., Franco, N.: Causal structure for noncommutative geometry. In: Frontiers of Fundamental Physics, vol. 14 (2015). PoS(FFP14)138

    Google Scholar 

  27. Eckstein, M., Franco, N., Miller, T.: Noncommutative geometry of Zitterbewegung. Phys. Rev. D 95, 061701(R) (2017)

    Article  ADS  Google Scholar 

  28. Eckstein, M., Zając, A.: Asymptotic and exact expansions of heat traces. Math. Phys. Anal. Geom. 18(1), 1–44 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  29. Estrada, R., Fulling, S.A.: Distributional asymptotic expansions of spectral functions and of the associated Green kernels. Electron. J. Differ. Equ. 07, 1–37 (1999)

    MathSciNet  MATH  Google Scholar 

  30. Fathizadeh, F., Khalkhali, M.: Twisted spectral triples and Connes’s character formula. In: Khalkhali, M., Yu, G. (eds.) Perspectives on Noncommutative Geometry, pp. 79–102. AMS, Providence (2011)

    Google Scholar 

  31. Fathizadeh, F., Khalkhali, M.: Scalar curvature for the noncommutative torus. J. Noncommutative Geom. 7, 1145–1183 (2013)

    Google Scholar 

  32. Franco, N.: Lorentzian approach to noncommutative geometry. Ph.D. thesis, University of Namur FUNDP (2011). arXiv:1108.0592 [math-ph]

  33. Franco, N.: Temporal Lorentzian spectral triples. Rev. Math. Phys. 26(08), 1430007 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  34. Franco, N., Eckstein, M.: An algebraic formulation of causality for noncommutative geometry. Class. Quantum Gravity 30(13), 135007 (2013)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  35. Franco, N., Eckstein, M.: Exploring the causal structures of almost commutative geometries. SIGMA 10, 010 (2014)

    MathSciNet  MATH  Google Scholar 

  36. Franco, N., Eckstein, M.: Causality in noncommutative two-sheeted space-times. J. Geom. Phys. 96, 42–58 (2015)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  37. Franco, N., Wallet, J.C.: Metrics and causality on Moyal planes. Noncommutative Geometry and Optimal Transport. Contemporary Mathematics, vol. 676, pp. 147–173. American Mathematical Society, Providence (2016)

    Chapter  MATH  Google Scholar 

  38. Gayral, V., Gracia-Bondía, J.M., Iochum, B., Schücker, T., Várilly, J.C.: Moyal planes are spectral triples. Commun. Math. Phys. 246(3), 569–623 (2004)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  39. Gayral, V., Iochum, B.: The spectral action for Moyal planes. J. Math. Phys. 46(4), 043503 (2005)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  40. Gayral, V., Wulkenhaar, R.: Spectral geometry of the Moyal plane with harmonic propagation. J. Noncommutative Geom. 7(4), 939–979 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  41. Greenfield, M., Marcolli, M., Teh, K.: Twisted spectral triples and quantum statistical mechanics. p-Adic numbers, ultrametric. Anal. Appl. 6(2), 81–104 (2014)

    MathSciNet  MATH  Google Scholar 

  42. Haag, R.: Local Quantum Physics: Fields, Particles, Algebras. Theoretical and Mathematical Physics. Springer, Berlin (1996)

    Book  MATH  Google Scholar 

  43. Hawkins, A., Skalski, A., White, S., Zacharias, J.: On spectral triples on crossed products arising from equicontinuous actions. Math. Scand. 113(2), 262–291 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  44. Higson, N., Roe, J.: Analytic K-Homology. Oxford University Press, Oxford (2000)

    MATH  Google Scholar 

  45. Iochum, B., Levy, C., Vassilevich, D.: Spectral action for torsion with and without boundaries. Commun. Math. Phys. 310(2), 367–382 (2012)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  46. Iochum, B., Masson, T.: Crossed product extensions of spectral triples. J. Noncommutative Geom. 10, 65–133 (2016)

    MathSciNet  MATH  Google Scholar 

  47. Iochum, B., Masson, T.: Heat asymptotics for nonminimal Laplace type operators and application to noncommutative tori. J. Geom. Phys. 129, 1–24 (2018)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  48. Kaad, J., Senior, R.: A twisted spectral triple for quantum \(SU(2)\). J. Geom. Phys. 62(4), 731–739 (2012)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  49. Keyl, M.: Fundamentals of quantum information theory. Phys. Rep. 369(5), 431–548 (2002)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  50. Landi, G., Martinetti, P.: On twisting real spectral triples by algebra automorphisms. Lett. Math. Phys. 106, 1499–1530 (2016)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  51. Matassa, M.: Quantum dimension and quantum projective spaces. SIGMA 10, 097 (2014)

    MathSciNet  MATH  Google Scholar 

  52. Matassa, M., Yuncken, R.: Regularity of twisted spectral triples and pseudodifferential calculi. J. Noncommutative Geom. (to appear). arXiv:1705.04178 [math.OA]

  53. Minguzzi, E.: Compactification of closed preordered spaces. Appl. Gen. Topol. 13(2), 207–223 (2012)

    MathSciNet  MATH  Google Scholar 

  54. Moscovici, H.: Local index formula and twisted spectral triples. Quanta of Maths. Clay Mathematics Proceedings, vol. 11, pp. 465–500. American Mathematical Society, Providence (2010)

    Google Scholar 

  55. Paschke, M., Sitarz, A.: Equivariant Lorentzian spectral triples (2006). arXiv:math-ph/0611029

  56. Ponge, R., Wang, H.: Index map, \(\sigma \)-connections, and Connes–Chern character in the setting of twisted spectral triples. Kyoto J. Math. 56(2), 347–399 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  57. Rennie, A.: Smoothness and locality for nonunital spectral triples. K-theory 28(2), 127–165 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  58. Rennie, A.: Summability for nonunital spectral triples. K-theory 31(1), 71–100 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  59. Schrohe, E.: Complex powers of elliptic pseudodifferential operators. Integral Equ. Oper. Theory 9(3), 337–354 (1986)

    Article  MathSciNet  MATH  Google Scholar 

  60. Sitarz, A.: Wodzicki residue and minimal operators on a noncommutative 4-dimensional torus. J. Pseudo-Differ. Oper. Appl. 5, 305–317 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  61. Strocchi, F.: An Introduction to the Mathematical Structure of Quantum Mechanics. World Scientific, New Jersey (2008)

    Book  MATH  Google Scholar 

  62. Strohmaier, A.: On noncommutative and pseudo-Riemannian geometry. J. Geom. Phys. 56(2), 175–195 (2006)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  63. van Suijlekom, W.D.: The noncommutative Lorentzian cylinder as an isospectral deformation. J. Math. Phys. 45(1), 537–556 (2004)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  64. Wald, R.M.: General Relativity. University of Chicago Press, Chicago (1984)

    Book  MATH  Google Scholar 

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Eckstein, M., Iochum, B. (2018). Open Problems. In: Spectral Action in Noncommutative Geometry. SpringerBriefs in Mathematical Physics, vol 27. Springer, Cham. https://doi.org/10.1007/978-3-319-94788-4_5

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