Skip to main content
Log in

Harmonic Analysis on Inhomogeneous Amenable Networks and the Bose–Einstein Condensation

  • Published:
Journal of Statistical Physics Aims and scope Submit manuscript

Abstract

We study in detail relevant spectral properties of the adjacency matrix of inhomogeneous amenable networks, and in particular those arising by negligible additive perturbations of periodic lattices. The obtained results are deeply connected to the systematic investigation of the Bose–Einstein condensation for the so called Pure Hopping model describing the thermodynamics of Cooper pairs in arrays of Josephson junctions. After a careful investigation of the infinite volume limits of the finite volume adjacency matrix corresponding to the (opposite of the) Hamiltonian of the system, the main results can be summarised as follows. First, the appearance of the Hidden Spectrum for the Integrated Density of the States in the region close to the bottom of the Hamiltonian, implies that the critical density is always finite. Second, we show that the Bose–Einstein condensation can appear if and only if the adjacency matrix is transient, and not just when the critical density is finite. We can then exhibit examples of networks for which condensation effects can appear in a natural way, even if the critical density is infinite and vice-versa, that is when the critical density is finite but the system does not admit any locally normal state exhibiting condensation. Contrarily to the known homogeneous examples, we also exhibit networks whose geometrical dimension is less than 3, for which the condensation takes place. Due to inhomogeneity, the spatial distribution of the condensate described by the shape of the ground state wave–function (i.e. the Perron–Frobenius weight), is non homogeneous as well: the particles condensate even in the configuration space. Such a spatial distribution of the condensate is connected with the Perron–Frobenius dimension defined in a natural way. For systems for which the critical density is finite and the adjacency matrix is transient, we show that, if the Perron–Frobenius dimension is greater that the geometrical one, we can have condensation only if the mean density of the state is infinite. Conversely, in the opposite situation when the geometrical dimension exceeds the Perron–Frobenius one, the condensation appears only for states with mean density coinciding with the critical one, that is the amount of the condensate is negligible with respect to the amount of the whole particles. All those states should satisfy the KMS boundary condition with respect to the natural dynamics generated by the formal Pure Hopping Hamiltonian. The existence of such a dynamics, which is a delicate issue, is provided in detail.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

Notes

  1. Concerning the appearance of the BEC for the cases under consideration, for further details we refer the reader to Proposition 3.1, and the related analysis in Sect. 3.

  2. By passing to a subsequence, it is easily shown that the sequence of finite volume PF eigenvectors as above, converges by compactness to a PF weight, see Proposition 4.1 of [8]. In all the situations considered in the present paper, the sequence of finite volume PF eigenvectors for the chosen exhaustion converges point-wise to a PF weight without passing to subsequences, as we will see below.

  3. The homogeneous cases \({\mathbb Z}^d\) is extensively treated in literature, whereas the recurrent examples for which the PF weight is normalisable (i.e. a PF eigenvector, necessarily unique up a phase factor) are trivial.

  4. It is possible to show that the PF weight is not unique, even for the Adjacency of a Comb Graph in the transient case.

  5. The choice of entire functions is only for the sake of convenence, see the last part of the proof of Theorem 4.5.

  6. It is also customary to fix the activity \(z:=e^{\beta \mu }\), instead of the chemical potential.

References

  1. Bardeen, J., Cooper, L.N., Schrieffer, J.R.: Microscopic theory of superconductivity. Phys. Rev. 106, 162–164 (1957)

    Article  MathSciNet  ADS  Google Scholar 

  2. Bratteli, O., Robinson, D.W.: Operator Algebras and Quantum Statistical Mechanics I. II, Springer, Berlin (1979, 1981)

  3. Burioni, R., Cassi, D., Rasetti, M., Sodano, P., Vezzani, A.: Bose–Einstein condensation on inhomogeneous complex networks. J. Phys. B 34, 4697–4710 (2001)

    Article  ADS  Google Scholar 

  4. Fannes, M., Pulè, J.V., Verbeure, A.: On Bose condensation. Helv. Phys. Acta 55, 391–399 (1982)

    MathSciNet  Google Scholar 

  5. Fidaleo, F.: Harmonic analysis on perturbed Cayley trees. J. Funct. Anal. 261, 604–634 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  6. Fidaleo, F.: Corrigendum to ”Harmonic analysis on perturbed Cayley Trees”. J. Funct. Anal. 262, 4634–4637 (2012)

    Article  MATH  MathSciNet  Google Scholar 

  7. Fidaleo, F.: Harmonic analysis on perturbed Cayley trees II: the Bose–Einstein condensation, Infin. Dimens. Anal. Quantum Probab. Relat. Top. 15, 1250024 (2012)

    Article  MathSciNet  Google Scholar 

  8. Fidaleo, F., Guido, D., Isola, T.: Bose Einstein condensation on inhomogeneous graphs, Infin. Dimens. Anal. Quantum Probab. Relat. Top. 14, 149–197 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  9. Janáček, J.: Variance of periodic measure of bounded set with random position. Commentat. Math. Univ. Carol. 47, 443–455 (2006)

    MATH  Google Scholar 

  10. Joyce, G.S.: On the simple cubic lattice Green function. Philos. Trans. R Soc. Lond. Ser. A 273, 583–610 (1973)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  11. Klaers, J., Schmitt, J., Vewinger, F., Weitz, M.: Bose-Einstein condensation of photons in an optical microcavity. Nature 468, 545–548 (2010)

    Article  ADS  Google Scholar 

  12. Kolmogorov, A.N., Fomine, S.V.: Eléments de la théorie des fonctions et de analyse fonctionnelle, MIR Moscou (1998)

  13. Landau, L.D.: The theory of superfuidity of helium II. J. Phys. USSR 5, 71–100 (1941)

    Google Scholar 

  14. Landau, L.D., Lifshits, E.M.: Statistical Physics. vol. 5, 3rd edn. Butterworth-Heinemann, Amsterdam (1980)

    Google Scholar 

  15. Lorenzo, M., et al.: On Bose–Einstein condensation in Josephson junctions star graph arrays. Phys. Lett. A 378, 655–658 (2014)

    Article  ADS  Google Scholar 

  16. Pulè, J.V., Verbeure, A., Zagrebnov, V.A.: On nonhomogeneous Bose condensation. J. Math. Phys. 46, 083301 (2005)

    Article  MathSciNet  ADS  Google Scholar 

  17. Royden, H.L., Fitzpatrick, P.M.: Real Analysis. Prentice Hall, New Jersey (2007)

    Google Scholar 

  18. Seneta, E.: Nonnegative Matrices and Markov Chains. Springer, Berlin (1981)

    Book  Google Scholar 

  19. van den Berg, M., Dorlas, T.C., Priezzhev, V.B.: The Boson gas on a Cayley Tree. J. Stat. Phys. 69, 307–328 (1992)

    Article  MATH  ADS  Google Scholar 

  20. van den Berg, M., Lewis, J.T., Pulè, J.V.: A general theory of Bose–Einstein condensation. Helv. Phys. Acta 59, 1271–1288 (1986)

    MathSciNet  Google Scholar 

  21. Van Mieghem, P.: Graph spectra for complex networks. Cambridge University Press, Cambridge (2011)

    MATH  Google Scholar 

Download references

Acknowledgments

The author kindly acknowledges Yuri Safarov for help in proving Proposition 5.7. He is also grateful to two anonymous referees whose suggestions contributed to improve the presentation of the present paper.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Francesco Fidaleo.

Additional information

A Berta con profonda stima e gratitudine.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Fidaleo, F. Harmonic Analysis on Inhomogeneous Amenable Networks and the Bose–Einstein Condensation. J Stat Phys 160, 715–759 (2015). https://doi.org/10.1007/s10955-015-1263-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10955-015-1263-4

Keywords

Mathematics Subject Classification

Navigation