Zobrazeno 1 - 10
of 249
pro vyhledávání: '"Tranberg, Anders"'
We present a method to compute real-time path integrals numerically, by Monte-Carlo sampling on near-Lefschetz thimbles. We present a collection of new tools, which together provide an alternative to existing methods such as the Generalised thimble.
Externí odkaz:
http://arxiv.org/abs/2410.12762
Autor:
Tranberg, Anders, Ungersbäck, Gerhard
We perform an analysis of a number of approximations and methods used in numerical simulations of real-time Kadanoff-Baym equations based on truncations of the 2PI effective action. We compare the loop expansion to the 1/N expansion and compare their
Externí odkaz:
http://arxiv.org/abs/2409.06398
Autor:
Geetha, Divyarani C., Tranberg, Anders
We consider the instabilities of field perturbations around a homogeneous background color-electric and/or -magnetic field in SU(2) pure gauge theory. We investigate a number of distinct cases of background magnetic and electric fields, and compute t
Externí odkaz:
http://arxiv.org/abs/2403.02859
Autor:
Tranberg, Anders, Ungersbäck, Gerhard
In certain models of inflation, the postinflationary reheating of the Universe is not primarily due to perturbative decay of the inflaton field into particles, but proceeds through a tachyonic instability. In the process, long-wavelength modes of an
Externí odkaz:
http://arxiv.org/abs/2312.08167
The physics of individual Q-balls and interactions between multiple Q-balls are well-studied in classical numerical simulations. Interesting properties and phenomena have been discovered, involving stability, forces, collisions and swapping of charge
Externí odkaz:
http://arxiv.org/abs/2312.01139
Autor:
Tranberg, Anders, Ungersbäck, Gerhard
Classical-statistical lattice simulations provide a useful approximation to out-of-equilibrium quantum field theory, but only for systems exhibiting large occupation numbers, and only for phenomena that are not intrinsically quantum mechanical in nat
Externí odkaz:
http://arxiv.org/abs/2206.08691
We apply the Generalised Thimble approach to the computation of exact path integrals and correlators in real-time quantum field theory. We first investigate the details of the numerical implementation and ways of optimizing the algorithm. We subseque
Externí odkaz:
http://arxiv.org/abs/2204.10101
Publikováno v:
JHEP 02 (2022) 121
The non-linear dynamics of long-wavelength cosmological fluctuations may be phrased in terms of an effective classical, but stochastic evolution equation. The stochastic noise represents short-wavelength modes that continually redshift into the long-
Externí odkaz:
http://arxiv.org/abs/2111.14503
Autor:
Tranberg, Anders.
Proefschrift Universiteit van Amsterdam.
Met lit. opg. - Met samenvatting in het Nederlands en Deens.
Met lit. opg. - Met samenvatting in het Nederlands en Deens.
Externí odkaz:
http://dare.uva.nl/document/72982
Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified as the expectation value of a quantum field, evolving in a quantum effective potential. The shape
Externí odkaz:
http://arxiv.org/abs/2011.12030