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Abstract
We construct the graviton twopoint function for a twoparameter family of
linear covariant gauges in ndimensional de Sitter space. The construction is
performed via the modesum method in the BunchDavies vacuum in the
Poincare patch, and a FierzPauli mass term is introduced to regularize the infrared (IR) divergences. The resulting twopoint function is de Sitterinvariant, and free of IR divergences in the massless limit (for a certain range of parameters) though analytic continuation with respect to the mass for the puregauge sector of the twopoint function is necessary for this result. This general result agrees with the propagator obtained by analytic continuation from the sphere [Phys. Rev. D 34, 3670 (1986); Class. Quant. Grav. 18, 4317 (2001)].
However, if one starts with strictly zero mass theory, the IR divergences are
absent only for a specific value of one of the two parameters, with the other
parameter left generic. These findings agree with recent calculations in the
Landau (exact) gauge [J. Math. Phys. 53, 122502 (2012)], where IR
divergences do appear in the spintwo (tensor) part of the twopoint function.
However, we find the strength (including the sign) of the IR divergence to be different from the one found in this reference.
linear covariant gauges in ndimensional de Sitter space. The construction is
performed via the modesum method in the BunchDavies vacuum in the
Poincare patch, and a FierzPauli mass term is introduced to regularize the infrared (IR) divergences. The resulting twopoint function is de Sitterinvariant, and free of IR divergences in the massless limit (for a certain range of parameters) though analytic continuation with respect to the mass for the puregauge sector of the twopoint function is necessary for this result. This general result agrees with the propagator obtained by analytic continuation from the sphere [Phys. Rev. D 34, 3670 (1986); Class. Quant. Grav. 18, 4317 (2001)].
However, if one starts with strictly zero mass theory, the IR divergences are
absent only for a specific value of one of the two parameters, with the other
parameter left generic. These findings agree with recent calculations in the
Landau (exact) gauge [J. Math. Phys. 53, 122502 (2012)], where IR
divergences do appear in the spintwo (tensor) part of the twopoint function.
However, we find the strength (including the sign) of the IR divergence to be different from the one found in this reference.
Original language  English 

Article number  124006 
Pages (fromto)  130 
Number of pages  30 
Journal  Physical Review D 
Volume  93 
Publication status  Published  2 Jun 2016 
Bibliographical note
© 2016 American Physical Society. This is an authorproduced version of the published paper. Uploaded in accordance with the publisher’s selfarchiving policy. Further copying may not be permitted; contact the publisher for details.Activities
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William Couto Correa de Lima
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