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A fast direct solver for nonlocal operators in wavelet coordinates

Harbrecht, Helmut ; Multerer, Michael

In: Journal of computational physics, 2021, vol. 428, p. 15 p

In this article, we consider fast direct solvers for nonlocal operators. The pivotal idea is to combine a wavelet representation of the system matrix, yielding a quasi- sparse matrix, with the nested dissection ordering scheme. The latter drastically reduces the fill-in during the factorization of the system matrix by means of a Cholesky decomposition or an LU decomposition, respectively. This...

Air and Friction in the Celestial Region: Some Medieval Solutions to the Difficulties of the Aristotelian Theory Con-cerning the Production of Celestial Heat

Panzica, Aurora

In: Early Medieval and Modern Science, 2019, vol. 24, no. 4, p. 367-390

This paper explores the medieval debates raised by problems with the Aristotelian theory of the pro-duction and transmission of solar heat presented in De Caelo II, 7 and Meteorologica I, 3. In these passages, Aristotle states that celestial heat is generated by the friction set up in the air by the motion of celestial bodies. This statement is difficult to reconcile with the Aristotelian...

Wavelets on the Two-Sphere and Other Conic Sections

Antoine, Jean-Pierre ; Vandergheynst, Pierre

In: Journal of Fourier Analysis and Applications, 2007, vol. 13, no. 4, p. 369-386

On the number of lattice points in a small sphere and a recursive lattice decoding algorithm

Meyer, Annika

In: Designs, Codes and Cryptography, 2013, vol. 66, no. 1-3, p. 375-390

Allan Sandage and the cosmic expansion

Tammann, G. ; Reindl, B.

In: Astrophysics and Space Science, 2012, vol. 341, no. 1, p. 3-14

Low-temperature flux growth of sulfates, molybdates, and tungstates of Ca, Sr, and Ba and investigation of doping with Mn 6 +

Romanyuk, Y.E. ; Ehrentraut, D. ; Pollnau, M. ; García-Revilla, S. ; Valiente, R.

In: Applied Physics A, 2004, vol. 79, no. 3, p. 613-618

Anisotropies in the cosmic microwave background: Theoretical foundations

Durrer, Ruth

In: International Journal of Theoretical Physics, 1997, vol. 36, no. 11, p. 2469-2487

Complex Data Processing: Fast Wavelet Analysis on the Sphere

Wiaux, Y. ; McEwen, J.D. ; Vielva, P.

In: Journal of Fourier Analysis and Applications, 2007, vol. 13, no. 4, p. 477-493

Cosmological magnetic fields: their generation, evolution and observation

Durrer, Ruth ; Neronov, Andrii

In: The Astronomy and Astrophysics Review, 2013, vol. 21, no. 1, p. 1-109

Calculation of the large- N limit of CMB anisotropies induced by global scalar fields

Kunz, Martin ; Durrer, Ruth

In: International Journal of Theoretical Physics, 1997, vol. 36, no. 11, p. 2489-2501