Results 241 to 250 of about 901,118 (265)

Type Pi 1?2 magnetic field pulsations

Space Science Reviews, 1981
The relationships of type Pi (broadband) pulsations to various other substorm-related phenomena are reviewed. Several of the more popular mechanisms for the origin of Pi activity are discussed in the light of the observations. There is only one mechanism in sight that tentatively accounts for observed characteristics of Pi 1–2 activity at auroral oval ...
R.R. Heacock, R.D. Hunsucker
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An ionospheric origin for Pi 1 micropulsations

Planetary and Space Science, 1976
Abstract Cosmic noise absorption pulsation events observed with fast response riometers at Macquarie Island in the southern auroral zone have almost always been accompanied by Pi 1 micropulsations. A cross-spectral analysis of fast response riometer data and vertical component induction magnetometer data for one such event showed that, after the low ...
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The K(Pi, 1)-conjecture for the affine braid groups

2003
The authors prove that the complement of the hyperplane arrangement associated to the complexified action of a Euclidean reflection group of type \(\widetilde A_n\) is a \(K(\pi,1)\) space. This is done using the fact that the associated affine braid group \(\widetilde{\mathcal A}\) can be embedded in a finite type Artin braid group.
Charney, Ruth, Peifer, David
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The $ K(\pi,1)$-property for smooth marked curves over finite fields

Izvestiya: Mathematics, 2015
In recent papers (for instance: [Doc. Math., J. DMV 12, 441--471 (2007; Zbl 1169.11048); J. Reine Angew. Math. 640, 203--235 (2010; Zbl 1193.14041)]) the second author studied the ``\(K(\pi, 1)\)-property for \(p\)'' (the definition which uses a Hochschild-Serre spectral sequence is given in \S 1.1 of the present paper) for arithmetic curves whose ...
Lebacque, Phillipe, Schmidt, Alexander
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Pi 1–2 magnetic field pulsations on dayside cleft field lines

Nature, 1977
TYPE Pi 1–2 magnetic field pulsations, T = 1–150 s, have a broad-band, noise-like character and a tendency to occur during active aurorae and magnetospheric substorms1,2. It is well-known that type Pi 1–2 magnetic field pulsations observed in the night–morning sector during magnetospheric substorms maximise in amplitudes along the auroral oval1,2.
R. R. HEACOCK, R. D. HUNSUCKER
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SMOOTH KNOTS IN A MANIFOLD OF HOMOTOPY TYPE $ K(\pi,1)$

Mathematics of the USSR-Izvestiya, 1975
The author studies the set of smooth isotopy classes of embeddings of a sphere in a manifold having homotopy type , where . He obtains an explicit expression for in terms of the group and the well-known Haefliger groups of knots and finite links of the sphere in?.Bibliography: 7 items.
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$${\mathbb{A}}^{1}$$ -Coverings, $${\pi }_{1}^{{\mathbb{A}}^{1} }({\mathbb{P}}^{n})$$ and $${\pi }_{1}^{{\mathbb{A}}^{1} }(S{L}_{n})$$

2012
A simplicial covering \(\mathcal{Y}\rightarrow \mathcal{X}\)is a morphism of spaces which has the unique right lifting property with respect to simplicially trivial cofibrations.
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AGROEKOLOŠKA ANALIZA STANJA KVALITETE TLA ISTRAŽNE BUŠOTINE PILJENICE-1 (Pi-1

2023
Temeljni cilj ove agroekološke analize je utvrditi trenutno (nulto) stanje kvalitete tla prije početka potencijalnog crpljenja ugljikovodika na istražnoj bušotini Piljenice-1. Zahvat u prostoru opisan ovim naftno-rudarskim projektom nalazi se na području Sisačko-moslavačke županije, općine Lipovljani, k.č. 874/1 i 876 k.o. Piljenice.
Perčin, Aleksandra, Kisić, Ivica, Galić, Marija   +2 more
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Lectures on Artin Groups and the $$K(\pi ,1)$$ Conjecture

2014
This paper consists of the notes of a mini-course (3 lectures) on Artin groups that focuses on a central question of the subject, the \(K(\pi ,1)\) conjecture.
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PUBLISHED PAPER ON TRUE Pi -1

2022
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