Zobrazeno 1 - 10
of 40
pro vyhledávání: '"Jochen Zahn"'
Autor:
Markus B. Fröb, Jochen Zahn
Publikováno v:
Journal of High Energy Physics, Vol 2019, Iss 10, Pp 1-40 (2019)
Abstract 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
Externí odkaz:
https://doaj.org/article/3cc01016d7974b14acd76e170b2a9d56
Autor:
Jochen Zahn
Publikováno v:
Nuclear Physics B, Vol 890, Iss , Pp 1-16 (2015)
We define chiral fermions in the presence of non-trivial gravitational and gauge background fields in the framework of locally covariant field theory. This allows to straightforwardly compute the chiral anomalies on non-compact Lorentzian spacetimes,
Externí odkaz:
https://doaj.org/article/7da5172d6a9c4b7abe45ed1894afec1f
Autor:
Harold Steinacker, Jochen Zahn
Publikováno v:
Symmetry, Integrability and Geometry: Methods and Applications, Vol 9, p 067 (2013)
We introduce an index indicating the occurrence of chiral fermions at the intersection of branes in matrix models. This allows to discuss the stability of chiral fermions under perturbations of the branes.
Externí odkaz:
https://doaj.org/article/dca4328c4b69407cb25c6a04f6d603dd
Autor:
Christoph Giese, Jochen Zahn
Publikováno v:
Physical Review D. 106
We study the dynamics of charged, spherically symmetric dust shells in the presence of a positive cosmological constant. We find generalizations of the well-known solutions in asymptotically flat spacetime, in particular orbits into "parallel univers
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f7a5ef57a6bf673959f02f6b63c6aee1
https://doi.org/10.1103/physrevd.106.064005
https://doi.org/10.1103/physrevd.106.064005
Publikováno v:
Physical Review
We compute semiclassical corrections to the energy density of kinks in $\phi^4$ theory and of solitons in the sine-Gordon model in $1+1$ dimensions, using local and covariant renormalization techniques from quantum field theory in curved spacetimes.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::160aefc296e11693a734ab1872b9d14b
http://arxiv.org/abs/2204.08785
http://arxiv.org/abs/2204.08785
Publikováno v:
Physical Review Letters. 127
We analyze the "vacuum" polarization induced by a quantum charged scalar field near the inner horizon of a charged (Reissner-Nordstr\"om-de Sitter) black hole in quantum states that start out as regular states near an initial Cauchy surface. Contrary
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2839f194002828abc81ea3f725177a86
https://doi.org/10.1103/physrevlett.127.231301
https://doi.org/10.1103/physrevlett.127.231301
Autor:
Christiane Klein, Jochen Zahn
Publikováno v:
Physical Review D. 104
We perform a Hadamard point-split renormalization of the current density $j_\nu$ of a charged scalar field in a Reissner-Nordstr\"om-de Sitter spacetime. We compute numerically the expectation values of the components $j_r$ and $j_t$ in the Unruh sta
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef1b0305dcfcc5b29622b7dfd5a56cb9
https://doi.org/10.1103/physrevd.104.025009
https://doi.org/10.1103/physrevd.104.025009
Autor:
Jochen Zahn, Jonathan Wernersson
Publikováno v:
Physical Review
We study the effect of boundary conditions on vacuum polarization for charged scalar fields in two space-time dimensions. We find that both Dirichlet and Neumann boundary conditions lead to screening. In the Dirichlet case, the vacuum polarization ch
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::52bd1f5378cc15b89aee3654d0547679
Autor:
Jochen Zahn
Publikováno v:
Annales Henri Poincaré. 19:163-187
We discuss a free scalar field subject to generalized Wentzell boundary conditions. On the classical level, we prove well-posedness of the Cauchy problem and in particular causality. Upon quantization, we obtain a field that may naturally be restrict
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f9f2ee245f0ae210c13624024a01978b
https://doi.org/10.1007/s00023-017-0629-3
https://doi.org/10.1007/s00023-017-0629-3
Autor:
Jochen Zahn, Markus B. Fröb
Publikováno v:
Journal of High Energy Physics
Journal of High Energy Physics, Vol 2019, Iss 10, Pp 1-40 (2019)
Journal of High Energy Physics, Vol 2019, Iss 10, Pp 1-40 (2019)
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 vanishi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::48387651a1ee79d9356afdea20059ad8