Physics Maths Engineering
Mohammad R. Garousi
Mohammad R. Garousi
Institution: Department of Physics, Faculty of Science, Ferdowsi University of Mashhad,
Email: garousi@um.ac.ir
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Doi: https://doi.org/10.1140/epjc/s10052-021-09952-6
2022-03-27Recently, using the assumption that the string theory effective action at the critical dimension is background independent, the classical on-shell effective action of the bosonic string theory at order α in a spacetime manifold without boundary has been reproduced, up to an overall parameter, by imposing the O(1, 1) symmetry when the background has a circle. In the presence of the boundary, we consider a background which has boundary and a circle such that the unit normal vector of the boundary is independent of the circle. Then the O(1, 1) symmetry can fix the bulk action without using the lowest order equation of motion. Moreover, the above constraints and the constraint from the principle of the least action in the presence of boundary can fix the boundary action, up to five boundary parameters. In the least action principle, we assume that not only the values of the massless fields but also the values of their first derivatives are arbitrary on the boundary. We have also observed that the cosmological reduction of the leading order action in the presence of the Hawking–Gibbons boundary term, produces zero cosmological boundary action. Imposing this as another constraint on the boundary couplings at order α, we find the boundary action up to two parameters. For a specific value for these two parameters, the gravity couplings in the boundary become the Chern–Simons gravity plus another term which has the Laplacian of the extrinsic curvature.
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Show by month | Manuscript | Video Summary |
---|---|---|
2024 September | 2 | 2 |
2024 August | 66 | 66 |
2024 July | 80 | 80 |
2024 June | 61 | 61 |
2024 May | 47 | 47 |
2024 April | 55 | 55 |
2024 March | 33 | 33 |
2024 February | 26 | 26 |
2024 January | 25 | 25 |
2023 December | 24 | 24 |
2023 November | 37 | 37 |
2023 October | 22 | 22 |
2023 September | 18 | 18 |
2023 August | 7 | 7 |
2023 July | 20 | 20 |
2023 June | 16 | 16 |
2023 May | 23 | 23 |
2023 April | 16 | 16 |
2023 March | 31 | 31 |
2023 January | 2 | 2 |
2022 December | 19 | 19 |
2022 November | 48 | 48 |
2022 October | 35 | 35 |
2022 September | 23 | 23 |
2022 August | 52 | 52 |
2022 July | 43 | 43 |
2022 June | 85 | 85 |
2022 May | 39 | 39 |
2022 April | 32 | 32 |
2022 March | 4 | 4 |
Total | 991 | 991 |