Search results for "induced [background]"
showing 10 items of 366 documents
A characteristic subgroup and kernels of Brauer characters
2005
If G is finite group and P is a Sylow p-subgroup of G, we prove that there is a unique largest normal subgroup L of G such that L ⋂ P = L ⋂ NG (P). If G is p-solvable, then L is the intersection of the kernels of the irreducible Brauer characters of G of degree not divisible by p.
Characters of relative p'-degree over normal subgroups
2013
Let Z be a normal subgroup of a finite group G , let ??Irr(Z) be an irreducible complex character of Z , and let p be a prime number. If p does not divide the integers ?(1)/?(1) for all ??Irr(G) lying over ? , then we prove that the Sylow p -subgroups of G/Z are abelian. This theorem, which generalizes the Gluck-Wolf Theorem to arbitrary finite groups, is one of the principal obstacles to proving the celebrated Brauer Height Zero Conjecture
On fully ramified Brauer characters
2014
Let Z be a normal subgroup of a finite group, let p≠5 be a prime and let λ∈IBr(Z) be an irreducible G-invariant p-Brauer character of Z. Suppose that λG=eφ for some φ∈IBr(G). Then G/Z is solvable. In other words, a twisted group algebra over an algebraically closed field of characteristic not 5 with a unique class of simple modules comes from a solvable group.
NONVANISHING ELEMENTS FOR BRAUER CHARACTERS
2015
Let $G$ be a finite group and $p$ a prime. We say that a $p$-regular element $g$ of $G$ is $p$-nonvanishing if no irreducible $p$-Brauer character of $G$ takes the value $0$ on $g$. The main result of this paper shows that if $G$ is solvable and $g\in G$ is a $p$-regular element which is $p$-nonvanishing, then $g$ lies in a normal subgroup of $G$ whose $p$-length and $p^{\prime }$-length are both at most 2 (with possible exceptions for $p\leq 7$), the bound being best possible. This result is obtained through the analysis of one particular orbit condition in linear actions of solvable groups on finite vector spaces, and it generalizes (for $p>7$) some results in Dolfi and Pacifici [‘Zero…
Thermal annealing and transformation of dimer F centers in neutron-irradiated Al2O3 single crystals
2020
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. In addition, the research leading to these results has received funding from the Estonian Research Council grant (PUT PRG619).
Production and investigation of multiply charged metal clusters in a Penning trap
1996
Singly charged gold cluster ions from a laser-vaporization source are transferred into a Penning trap and subjected to electron bombardment. The charged reaction products are analyzed by time-of-flight mass spectrometry after axial ejection from the trap. They include singly charged cluster fragments, multiply charged clusters of the initial size and multiply charged cluster fragments. The multiply charged clusters are selected and further investigated by collision induced dissociation. Two types of reactions can be distinguished: Dissociation into several charged fragments and evaporation of neutrals. Several features of multiply charged clusters relevant for future investigations are revi…
Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers
2019
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Work performed under EUROfusion WP PFC.
Measurements of forward proton production with incident protons and charged pions on nuclear targets at the CERN Proton Synchroton
2010
Measurements of the double-differential proton production cross-section d(2 sigma)/dpd Omega in the range of momentum 0.5 GeV/c <= p < 8.0 GeV/c and angle 0.05 rad <= theta < 0.25 rad in collisions of charged pions and protons on beryllium, carbon, aluminium, copper, tin, tantalum, and lead are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN Proton Synchrotron. Incident particles were identified by an elaborate system of beam detectors and impinged on a target of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using the forward spectrometer of the HARP experiment. Results are o…
The Nuclear astrophysics program at n_TOF (CERN)
2017
An important experimental program on Nuclear Astrophysics is being carried out at the n_TOF since several years, in order to address the still open issues in stellar and primordial nucleosynthesis. Several neutron capture reactions relevant to s-process nucleosynthesis have been measured so far, some of which on important branching point radioisotopes. Furthermore, the construction of a second experimental area has recently opened the way to challenging measurements of (n, charged particle) reactions on isotopes of short half-life. The Nuclear Astrophysics program of the n_TOF Collaboration is here described, with emphasis on recent results relevant for stellar nucleosynthesis, stellar neut…
New constraints on the Al 25 (p,γ) reaction and its influence on the flux of cosmic γ rays from classical nova explosions
2021
The astrophysical Al25(p,γ)Si26 reaction represents one of the key remaining uncertainties in accurately modeling the abundance of radiogenic Al26 ejected from classical novae. Specifically, the strengths of key proton-unbound resonances in Si26, that govern the rate of the Al25(p,γ) reaction under explosive astrophysical conditions, remain unsettled. Here, we present a detailed spectroscopy study of the Si26 mirror nucleus Mg26. We have measured the lifetime of the 3+, 6.125-MeV state in Mg26 to be 19(3)fs and provide compelling evidence for the existence of a 1- state in the T=1,A=26 system, indicating a previously unaccounted for=1 resonance in the Al25(p,γ) reaction. Using the presently…