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Helmut Wielandt (December 19, 1910 – February 14, 2001) was a German mathematician known primarily for his influential work in group theory. He made pioneering contributions to the study of subnormal subgroups and other structural aspects of finite groups. Wielandt served as a professor at several German universities, including the University of Tübingen, and authored important texts on finite groups and permutation groups. His work left a lasting impact on modern algebra.

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We present in this note a maximum-minimum characterization of sums like a3+a7+asj where a1> . * * a. are the eigenvalues of a hermitian nXn matrix. The result contains the … We present in this note a maximum-minimum characterization of sums like a3+a7+asj where a1> . * * a. are the eigenvalues of a hermitian nXn matrix. The result contains the classic characterization of am as well as the maximum property of a1+a2+ * * * +a. given recently by Fan [4]. Though the result is valid also for a completely continuous hermitian operator in Hilbert space, we shall for the sake of simplicity assume the dimension to be finite. As an application we obtain linear inequalities relating the eigenvalues of the sum of two hermitian matrices to the eigenvalues of the summands.
Ein Teil von Philip Halls bekannter Theorie der auflösbaren Gruppen läßt sich, wie im folgenden gezeigt wird, auf beliebige endiliche Gruppen G ausdehnen. Wir fragen: Was kann man über die … Ein Teil von Philip Halls bekannter Theorie der auflösbaren Gruppen läßt sich, wie im folgenden gezeigt wird, auf beliebige endiliche Gruppen G ausdehnen. Wir fragen: Was kann man über die Normalstruktur (Hauptreihen, Kompositionsfaktoren) von G aussagen, wenn man mehrere Zer legungen von G in Produkte von Untergruppen mit gegebener Normalstruktur kennt? Eine Antwort gibt der folgende Satz, das Hauptergebnis dieser Note:
A short proof is given , under weaker ass ump tions, of t he foll owi ng theore m firs t proverl by K. Wiegman n: If t he e … A short proof is given , under weaker ass ump tions, of t he foll owi ng theore m firs t proverl by K. Wiegman n: If t he e igenvalu es a i, /3i of t wo normal n X n matrices A, B may be nUIllbered in s uch a wa .vthat t he eigen values I' i(Z) of C ( z )= a +zb are given by I'i(Z) = I' i+ Z/3 i (fo r i =
Ein Teil von Philip Halls bekannter Theorie der auflösbaren Gruppen läßt sich, wie im folgenden gezeigt wird, auf beliebige endiliche Gruppen G ausdehnen. Wir fragen: Was kann man über die … Ein Teil von Philip Halls bekannter Theorie der auflösbaren Gruppen läßt sich, wie im folgenden gezeigt wird, auf beliebige endiliche Gruppen G ausdehnen. Wir fragen: Was kann man über die Normalstruktur (Hauptreihen, Kompositionsfaktoren) von G aussagen, wenn man mehrere Zer legungen von G in Produkte von Untergruppen mit gegebener Normalstruktur kennt? Eine Antwort gibt der folgende Satz, das Hauptergebnis dieser Note:
We present in this note a maximum-minimum characterization of sums like a3+a7+asj where a1> . * * a. are the eigenvalues of a hermitian nXn matrix. The result contains the … We present in this note a maximum-minimum characterization of sums like a3+a7+asj where a1> . * * a. are the eigenvalues of a hermitian nXn matrix. The result contains the classic characterization of am as well as the maximum property of a1+a2+ * * * +a. given recently by Fan [4]. Though the result is valid also for a completely continuous hermitian operator in Hilbert space, we shall for the sake of simplicity assume the dimension to be finite. As an application we obtain linear inequalities relating the eigenvalues of the sum of two hermitian matrices to the eigenvalues of the summands.
A short proof is given , under weaker ass ump tions, of t he foll owi ng theore m firs t proverl by K. Wiegman n: If t he e … A short proof is given , under weaker ass ump tions, of t he foll owi ng theore m firs t proverl by K. Wiegman n: If t he e igenvalu es a i, /3i of t wo normal n X n matrices A, B may be nUIllbered in s uch a wa .vthat t he eigen values I' i(Z) of C ( z )= a +zb are given by I'i(Z) = I' i+ Z/3 i (fo r i =
is any set of characteristics, and Xp Xj* •••» Xr a set for which \\ is unity, then XiXi» X2X2' • " ' X r X r is a set … is any set of characteristics, and Xp Xj* •••» Xr a set for which \\ is unity, then XiXi» X2X2' • " ' X r X r is a set of characteristics.Returning to the irreducible representation of the group in the form «,' -"?* n e £x* (x* +1) homogeneous products of the second degree of the x's are transformed lineai'ly among themselves by every operation of the group; and, for this representation, the sum of the multipliers of any operation is equal to the sum of the homogeneous products two together of the multipliers in the above irreducible form.Hence, by similar reasoning to that employed above, there must be positive integers e,-,, such thatwhere 4*1 ia the sum of the homogeneous products two together of the multipliers whose sum is xi-In this way it may be shown that, if any symmetric function be formed of x' symbols, a system of equations of the form (ii), in which the e's are positive integers, must hold when i/^ is the symmetric function formed.from, the multipliers whose sum is xi-In particular, the products of the multipliers for each set of conjugate operations in any representation of the group constitutes a set of characteristics for which \i 18 unity.On some Properties of Groins of Odd Order.By W. BURNSIDE.
If there is given a subgroup 5 of a (finite) group G, we may ask what information is to be obtained about the structure of G from a knowledge of … If there is given a subgroup 5 of a (finite) group G, we may ask what information is to be obtained about the structure of G from a knowledge of the location of S in G. Thus, for example, famed theorems of Frobenius and Burnside give criteria for the existence of a normal subgroup N of G such that G = NS and 1 = N ⋂ S, and hence in particular for the non-simplicity of G. To aid in locating S in G, and to facilitate exploitation of the transfer, we single out a descending chain of normal subgroups of S. Namely, we introduce the focal series of S in G by means of the recursive formulae
COROLLARY 2. // i(H)=B 9 then G has a normal subgroup K such that <B B .Proof.Let N(H) denote the normalizer of H, and Cί(H) the conjugate class of H. … COROLLARY 2. // i(H)=B 9 then G has a normal subgroup K such that <B B .Proof.Let N(H) denote the normalizer of H, and Cί(H) the conjugate class of H. Then
It is well-known that the Perron root of a nonnegative irreducible matrix lies between the smallest and the largest row sum of A. This result is generalized to the case … It is well-known that the Perron root of a nonnegative irreducible matrix lies between the smallest and the largest row sum of A. This result is generalized to the case when the matrix A is partitioned into blocks.
In terms of the coefficients OC, jS, γ of a defining equation of a cubic field F over the rational number field Q 9 Albert [l] has given an explicit … In terms of the coefficients OC, jS, γ of a defining equation of a cubic field F over the rational number field Q 9 Albert [l] has given an explicit formula for a minimal basis, that is, a basis of the integers of Q{θ) over the rational integers.We solve this same problem with a shorter proof and a simpler result.This basis is then used to find the maximal inessential discriminant divisor, that is, the square root of the quotient of the g.c.d. of the discriminants of all integers of Q(θ) by the discriminant of Q(θ).It is known[3] that the only prime dividing it is 2; we determine the power as 2° or 2 ι .We first secure a normalized generating quantity, LEMMA 1.If K is any cubic field, then K = Q(θ) with (2) 6> 3 + aθ 2 + 6 = 0, where (i) a and b are rational integers, (ii) no factor of a has its cube dividing b 9 and (iii) if 3 \\a, then the discriminant Δ =b (4α 3 + 27 b) of θ is not divisible by 3 4 unless 3 | b.Here g n |1 y means g n | γ and g n l \γ.Proof.The substitution θ'~ θ+ α/3 is used to obtain an equation of form(1) with α zero.Follow this by the substitution 0'= 1/0 to obtain (2).For Conditions (i) and (ii) it is obvious that a substitution 0'= hθ will be effective.If (iii) does not hold apply the substitution 0'= ab -3 bθ + a 2 θ 2 ; then 0' 3 + cθ' 2 +d = 0 where
We studied the bounds of Perron root of a nonnegative matrix, and defined the 1-path cover of directed graph. With the help of the directed graph and 1-path cover of … We studied the bounds of Perron root of a nonnegative matrix, and defined the 1-path cover of directed graph. With the help of the directed graph and 1-path cover of directed graph, we gave a new method to estimate the super bounds and lower bounds of Perron root of a nonnegative matrix, and obtained some new results.