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Trace anomaly for chiral fermions via Hadamard subtraction. (English) Zbl 1427.83100

Summary: We calculate the trace (conformal) anomaly for chiral fermions in a general curved background using Hadamard subtraction. While in intermediate steps of the calculation imaginary terms proportional to the Pontryagin density appear, imposing a vanishing divergence of the stress tensor these terms completely cancel, and we recover the well-known result equal to half the trace anomaly of a Dirac fermion. We elaborate in detail on the advantages of the Hadamard method for the general definition of composite operators in general curved spacetimes, and speculate on possible causes for the appearance of the Pontryagin density in other calculations.

MSC:

83E30 String and superstring theories in gravitational theory
81T50 Anomalies in quantum field theory
83C47 Methods of quantum field theory in general relativity and gravitational theory

Software:

xAct

References:

[1] Bonora, L.; Giaccari, S.; Lima de Souza, B., Trace anomalies in chiral theories revisited, JHEP, 07, 117 (2014) · Zbl 1317.81237
[2] Nakayama, Y., CP-violating CFT and trace anomaly, Nucl. Phys., B 859, 288 (2012) · Zbl 1246.81328
[3] Nakayama, Y., Realization of impossible anomalies, Phys. Rev., D 98, 085002 (2018)
[4] Bastianelli, F.; Martelli, R., On the trace anomaly of a Weyl fermion, JHEP, 11, 178 (2016) · Zbl 1390.83323
[5] Bonora, L.; Cvitan, M.; Dominis Prester, P.; Duarte Pereira, A.; Giaccari, S.; Štemberga, T., Axial gravity, massless fermions and trace anomalies, Eur. Phys. J., C 77, 511 (2017)
[6] Bonora, L.; Cvitan, M.; Prester, PD; Pereira, AD; Giaccari, S.; Štemberga, T., Pontryagin trace anomaly, EPJ Web Conf., 182, 02100 (2018)
[7] Zahn, J., Locally covariant chiral fermions and anomalies, Nucl. Phys., B 890, 1 (2014) · Zbl 1326.81135
[8] Hollands, S.; Wald, RM, Quantum fields in curved spacetime, Phys. Rept., 574, 1 (2015) · Zbl 1357.81144
[9] C. Misner, K. Thorne and J.A. Wheeler, Gravitation, W.H. Freeman, San Francisco (1973) [INSPIRE].
[10] J. Hadamard, Le problème de Cauchy et les équations aux dérivées partielles lińeaires hyperboliques (in French), Hermann et Cie., Paris, France (1932). · Zbl 0006.20501
[11] C. Bär, N. Ginoux and F. Pfäffle, Wave Equations on Lorentzian Manifolds and Quantization, European Mathematical Society Publishing House, Zürich, Switzerland (2007) [arXiv:0806.1036]. · Zbl 1118.58016
[12] Fulling, S. A.; Narcowich, F. J.; Wald, Robert M., Singularity structure of the two-point function in quantum field theory in curved spacetime, II, Annals of Physics, 136, 243-272 (1981) · Zbl 0495.35054
[13] Fulling, SA; Sweeny, M.; Wald, RM, Singularity Structure of the Two Point Function in Quantum Field Theory in Curved Space-Time, Commun. Math. Phys., 63, 257 (1978) · Zbl 0401.35065
[14] H. Sahlmann and R. Verch, Microlocal spectrum condition and Hadamard form for vector valued quantum fields in curved space-time, Rev. Math. Phys.13 (2001) 1203 [math-ph/0008029] [INSPIRE]. · Zbl 1029.81053
[15] Sanders, K., The locally covariant Dirac field, Rev. Math. Phys., 22, 381 (2010) · Zbl 1216.81113
[16] H. Sahlmann and R. Verch, Passivity and microlocal spectrum condition, Commun. Math. Phys.214 (2000) 705 [math-ph/0002021] [INSPIRE]. · Zbl 1010.81046
[17] L. Parker and D. Toms, Quantum Field Theory in Curved Spacetime: Quantized Fields and Gravity, Cambridge University Press, Cambridge, U.K. (2009) [INSPIRE]. · Zbl 1180.81001
[18] Pinamonti, N., Conformal generally covariant quantum field theory: The Scalar field and its Wick products, Commun. Math. Phys., 288, 1117 (2009) · Zbl 1171.81021
[19] Olbermann, H., States of low energy on Robertson-Walker spacetimes, Class. Quant. Grav., 24, 5011 (2007) · Zbl 1206.83171
[20] Them, K.; Brum, M., States of Low Energy in Homogeneous and Inhomogeneous, Expanding Spacetimes, Class. Quant. Grav., 30, 235035 (2013) · Zbl 1284.83024
[21] K.-T. Pirk, Hadamard states and adiabatic vacua, Phys. Rev.D 48 (1993) 3779 [gr-qc/9211003] [INSPIRE].
[22] S. Hollands, The Hadamard condition for Dirac fields and adiabatic states on Robertson-Walker space-times, Commun. Math. Phys.216 (2001) 635 [gr-qc/9906076] [INSPIRE]. · Zbl 0976.58023
[23] W. Junker and E. Schrohe, Adiabatic vacuum states on general space-time manifolds: Definition, construction and physical properties, Annales Henri Poincaré3 (2002) 1113 [math-ph/0109010] [INSPIRE]. · Zbl 1038.81052
[24] R. Brunetti and K. Fredenhagen, Microlocal analysis and interacting quantum field theories: Renormalization on physical backgrounds, Commun. Math. Phys.208 (2000) 623 [math-ph/9903028] [INSPIRE]. · Zbl 1040.81067
[25] Fewster, CJ; Verch, R., The Necessity of the Hadamard Condition, Class. Quant. Grav., 30, 235027 (2013) · Zbl 1284.83057
[26] J.L. Synge, Relativity: The General Theory, North-Holland, Amsterdam, The Netherlands (1960) [INSPIRE]. · Zbl 0090.18504
[27] V. Moretti, Proof of the symmetry of the off diagonal Hadamard/Seeley-deWitt’s coefficients in C^∞Lorentzian manifolds by a “local Wick rotation”, Commun. Math. Phys.212 (2000) 165 [gr-qc/9908068] [INSPIRE]. · Zbl 0956.58019
[28] S. Hollands and R.M. Wald, Conservation of the stress tensor in interacting quantum field theory in curved spacetimes, Rev. Math. Phys.17 (2005) 227 [gr-qc/0404074] [INSPIRE]. · Zbl 1078.81062
[29] Y. Decanini and A. Folacci, Hadamard renormalization of the stress-energy tensor for a quantized scalar field in a general spacetime of arbitrary dimension, Phys. Rev.D 78 (2008) 044025 [gr-qc/0512118] [INSPIRE].
[30] DeWitt, BS; Brehme, RW, Radiation damping in a gravitational field, Annals Phys., 9, 220 (1960) · Zbl 0092.45003
[31] Dirac, PAM, Discussion of the infinite distribution of electrons in the theory of the positron, Proc. Camb. Phil. Soc., 30, 150 (1934) · JFM 60.0790.02
[32] J.S. Schwinger, The Theory of quantized fields. 1., Phys. Rev.82 (1951) 914 [INSPIRE]. · Zbl 0043.42202
[33] DeWitt, BS, Quantum Field Theory in Curved Space-Time, Phys. Rept., 19, 295 (1975)
[34] Christensen, SM, Vacuum Expectation Value of the Stress Tensor in an Arbitrary Curved Background: The Covariant Point Separation Method, Phys. Rev., D 14, 2490 (1976)
[35] Christensen, SM, Regularization, Renormalization and Covariant Geodesic Point Separation, Phys. Rev., D 17, 946 (1978)
[36] Uehling, EA, Polarization effects in the positron theory, Phys. Rev., 48, 55 (1935) · Zbl 0012.13605
[37] C.J. Fewster and R. Verch, Dynamical locality and covariance: What makes a physical theory the same in all spacetimes?, Annales Henri Poincaŕe13 (2012) 1613 [arXiv:1106.4785] [INSPIRE]. · Zbl 1280.81099
[38] Fewster, CJ, The art of the state, Int. J. Mod. Phys., D 27, 1843007 (2018) · Zbl 1430.81059
[39] S. Hollands and R.M. Wald, Local Wick polynomials and time ordered products of quantum fields in curved space-time, Commun. Math. Phys.223 (2001) 289 [gr-qc/0103074] [INSPIRE]. · Zbl 0989.81081
[40] S. Hollands and R.M. Wald, Existence of local covariant time ordered products of quantum fields in curved space-time, Commun. Math. Phys.231 (2002) 309 [gr-qc/0111108] [INSPIRE]. · Zbl 1015.81043
[41] Poisson, E.; Pound, A.; Vega, I., The Motion of point particles in curved spacetime, Living Rev. Rel., 14, 7 (2011) · Zbl 1316.83024
[42] V. Moretti, Comments on the stress energy tensor operator in curved space-time, Commun. Math. Phys.232 (2003) 189 [gr-qc/0109048] [INSPIRE]. · Zbl 1015.81044
[43] Y. Décanini and A. Folacci, Off-diagonal coefficients of the Dewitt-Schwinger and Hadamard representations of the Feynman propagator, Phys. Rev.D 73 (2006) 044027 [gr-qc/0511115] [INSPIRE].
[44] Forger, M.; Römer, H., Currents and the energy momentum tensor in classical field theory: A Fresh look at an old problem, Annals Phys., 309, 306 (2004) · Zbl 1062.70049
[45] Kennedy, AD, Clifford Algebras in 2ω Dimensions, J. Math. Phys., 22, 1330 (1981)
[46] Zahn, J., The renormalized locally covariant Dirac field, Rev. Math. Phys., 26, 1330012 (2014) · Zbl 1287.81086
[47] J.M. Martín-García et al., xAct: Efficient tensor computer algebra for the Wolfram Language, http://www.xact.es (2018).
[48] Lovelock, D., Dimensionally dependent identities, Proc. Camb. Phil. Soc., 68, 345 (1970) · Zbl 0197.48301
[49] S.B. Edgar and A. Höglund, Dimensionally dependent tensor identities by double antisymmetrization, J. Math. Phys.43 (2002) 659 [gr-qc/0105066] [INSPIRE]. · Zbl 1052.53022
[50] Dappiaggi, C.; Hack, T-P; Pinamonti, N., The Extended algebra of observables for Dirac fields and the trace anomaly of their stress-energy tensor, Rev. Math. Phys., 21, 1241 (2009) · Zbl 1231.81062
[51] Christensen, SM; Duff, MJ, New Gravitational Index Theorems and Supertheorems, Nucl. Phys., B 154, 301 (1979) · Zbl 0967.83535
[52] M.R. Mehta, Euclidean Continuation of the Dirac Fermion, Phys. Rev. Lett.65 (1990) 1983 [Erratum ibid.66 (1991) 522] [INSPIRE]. · Zbl 1050.81574
[53] Nieuwenhuizen, P.; Waldron, A., On Euclidean spinors and Wick rotations, Phys. Lett., B 389, 29 (1996)
[54] Wetterich, C., Spinors in euclidean field theory, complex structures and discrete symmetries, Nucl. Phys., B 852, 174 (2011) · Zbl 1229.81168
[55] Kupsch, J.; Thacker, WD, Euclidean Majorana and Weyl Spinors, Fortsch. Phys., 38, 35 (1990)
[56] Breitenlohner, P.; Maison, D., Dimensional Renormalization and the Action Principle, Commun. Math. Phys., 52, 11 (1977)
[57] G. ’t Hooft and M.J.G. Veltman, Regularization and Renormalization of Gauge Fields, Nucl. Phys.B 44 (1972) 189 [INSPIRE].
[58] Kreimer, D., The γ_5-problem and anomalies: A Clifford algebra Approach, Phys. Lett., B 237, 59 (1990)
[59] J.G. Körner, D. Kreimer and K. Schilcher, A Practicable γ_5-scheme in dimensional regularization, Z. Phys.C 54 (1992) 503 [INSPIRE].
[60] Thompson, G.; Yu, HL, γ_5in dimensional regularization, Phys. Lett., 151B, 119 (1985)
[61] Bonneau, G., Trace and Axial Anomalies in Dimensional Renormalization Through Zimmermann Like Identities, Nucl. Phys., B 171, 477 (1980)
[62] Bonneau, G., Consistency in Dimensional Regularization With γ_5, Phys. Lett., 96B, 147 (1980)
[63] Bonneau, G., Preserving Canonical Ward Identities in Dimensional Regularization With a Nonanticommuting γ_5, Nucl. Phys., B 177, 523 (1981)
[64] Baikov, PA; Il’in, VA, Status of γ^5in dimensional regularization, Theor. Math. Phys., 88, 789 (1991)
[65] L. Bonora, M. Cvitan, P. Dominis Prester, S. Giaccari, M. Paulǐsíc and T. Štemberga, Axial gravity: a non-perturbative approach to split anomalies, Eur. Phys. J.C 78 (2018) 652 [arXiv:1807.01249] [INSPIRE].
[66] Bastianelli, F.; Broccoli, M., On the trace anomaly of a Weyl fermion in a gauge background, Eur. Phys. J., C 79, 292 (2019)
[67] Dreiner, HK; Haber, HE; Martin, SP, Two-component spinor techniques and Feynman rules for quantum field theory and supersymmetry, Phys. Rept., 494, 1 (2010)
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