Quantum-Gravitational Diffusion and Stochastic Fluctuations in the Velocity of Light
Tóm tắt
We argue that quantum-gravitational fluctuations in the space-time background give the vacuum non-trivial optical properties that include diffusion and consequent uncertainties in the arrival times of photons, causing stochastic fluctuations in the velocity of light in vacuo. Our proposal is motivated within a Liouville string formulation of quantum gravity that also suggests a frequency-dependent refractive index of the particle vacuum. We construct an explicit realization by treating photon propagation through quantum excitations of D-brane fluctuations in the space-time foam. These are described by higher-genus string effects, that lead to stochastic fluctuations in couplings, and hence in the velocity of light. We discuss the possibilities of constraining or measuring photon diffusion in vacuo via γ-ray observations of distant astrophysical sources.
Tài liệu tham khảo
Amelino-Camelia, G., Ellis, J., Mavromatos, N. E. and Nanopoulos, D. V. (1997). Int. J. Mod. Phys. A 12, 607.
Amelino-Camelia, G., Ellis, J., Mavromatos, N. E., Nanopoulos, D. V. and Sarkar, S. (1998). Nature 393, 323; and astro-ph/9810483.
Gambini, R., and Pullin, J. (1999). Phys. Rev. D 59, 124021.
Halzen, F. (1999). Preprint astro-ph/9904216.
Ellis, J., Mavromatos, N. E. and Nanopoulos, D. V. (1992). Phys. Lett. B 293, 37; id. (1995). Int. School of Subnuclear Physics: 31st Course: From Supersymmetry to the Origin of Space-Time (Erice, 4-12 July, 1993) (Erice Subnuclear Series, Vol. 31, World Scientific, Singapore), 1.
David, F. (1988). Mod. Phys. Lett. A 3, 1651; Distler, J., and Kawai, H. (1989). Nucl. Phys. B 321, 509; see also Mavromatos, N. E. and Miramontes, J. L. (1989). Mod. Phys. Lett. A 4, 1847.
Kogan, I. (1992). In Particles and Fields 1991, D. Axen, D. Bryman and M. Comyn, eds. (World Scientific, Singapore), 837.
Zamolodchikov, A. B. (1986). JETP Lett. 43, 730; (1987). Sov. J. Nucl. Phys. 46, 1090.
Klebanov, I. R.,. Kogan, I.I, and Polyakov, A. M. (1993). Phys. Rev. Lett. 71, 3243; Schmidhuber, C. (1993). Nucl. Phys. B 404, 342.
Dorn, H. (1995). Phys. Lett. B 343, 81.
Antoniadis, I., Bachas, C., Ellis, J. and Nanopoulos, D. V. (1988). Phys. Lett. B 211, 383; (1989). Nucl. Phys. B 328, 117.
Ellis, J., Hagelin, J., Nanopoulos, D. V., and Srednicki, M. (1984). Nucl. Phys. B 241, 381.
Ellis, J., Kanti, P., Mavromatos, N. E., Nanopoulos, D. V., and Winstanley, E. (1998). Mod. Phys. Lett. A 13, 303, and references therein.
Polchinski, J. (1995). Phys. Rev. Lett. 75, 184; id. (1996). TASI lectures on D-branes, hep-th/9611050; Bachas, C. P. (1998). Lectures on D-branes, hep-th/9806199.
Ellis, J., Mavromatos, N. E., and Nanopoulos, D. V. (1995). Mod. Phys. Lett. A 10, 1685.
Lizzi, F., and Mavromatos, N. E. (1997). Phys. Rev. D 55, 7859.
Mavromatos, N. E. and Szabo, R. J. (1999). Phys. Rev. D 59, 064023, 104018.
Kogan, I. I., Mavromatos, N. E., and Wheater, J. F. (1996). Phys. Lett. B 387, 483.
Ellis, J., Mavromatos, N. E., and Nanopoulos, D. V. (1997). Int. J. Mod. Phys. A 12, 2639; (1998). ibid. A 13, 1059.
Tseytlin, A. A. (1997). Nucl. Phys. B 501, 41.
Fischler, W., and Susskind, L. (1986). Phys. Lett. B 171, 383; (1986). ibid. B 173, 262.
Li, M., and Yoneya, T. (1997). Phys. Rev. Lett. 78, 1219; for a recent review of space-time uncertainty relations in string theory, see Li, M., and Yoneya, T. (1998). Preprint hep-th/9806240.
Veneziano, G. (1986). Europhys. Lett. 2, 199; Gross, D. J., and Mende, P. F. (1988). Nucl. Phys. B 303, 407; Amati, D., Ciafaloni, M., and Veneziano, G. (1989). Phys. Lett. B 216, 41; Konishi, K., Paffuti, G., and Provero, P. (1990). Phys. Lett. B 234, 276.
Abouelsaood, A., Callan, C. G. Nappi, C. R., Yost, S. A. (1987). Nucl. Phys. B 280, 599.
Dorn, H. (1998). J. HighEner gy Phys. 4, 13, and references therein.
Amelino-Camelia, G. (1999). Nature 398, 216 and gr-qc/9903080.
Biller, S. D. et. al. (1998). Preprint gr-qc/9810044.
Kaaret, P. (1999). Preprint astro-ph/9903464.
Ahlen, S. et al. (1994). Nucl. Instrum. Meth. A 350, 351.
GLAST Team, Bloom, E. D., et al. (1996). Proc. Int. Heidelberg Workshop on TeV Gamma-Ray Astrophysics, H. J. Volk and F. A. Aharonian, eds. (Kluwer, Dordrecht), 109.