Stanley Orlando Juriaans
@ime.usp.br
Associate professor of IME-USP
University of São Paulo
From Suriname and living for over 30 years in Brazil
EDUCATION
Ph.D. in Mathematics
RESEARCH, TEACHING, or OTHER INTERESTS
Mathematics
FUTURE PROJECTS
Generalized QM
Applying generalized function theory to QM
Applications Invited
collaborators
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
W. Rodrigues, A. R. G. Garcia, S. O. Juriaans, and J. C. Silva
Monatshefte fur Mathematik Springer Science and Business Media LLC
A. R. G. Garcia, S. O. Juriaans, J. Oliveira, and W. M. Rodrigues
Sao Paulo Journal of Mathematical Sciences Springer Science and Business Media LLC
J. F. Colombeau, J. Aragona, P. Catuogno, S. O. Juriaans, and C. Olivera
Springer Singapore
E. Jespers, S. O. Juriaans, A. Kiefer, A. de A. e Silva, and A. C. Souza Filho
The Belgian Mathematical Society
We continue investigations started by Lakeland on Fuchsian and Kleinian groups which have a Dirichlet fundamental domain that also is a Ford domain in the upper half-space model of hyperbolic $2$- and $3$-space, or which have a Dirichlet domain with multiple centers. Such domains are called DF-domains and Double Dirichlet domains respectively. Making use of earlier obtained concrete formulas for the bisectors defining the Dirichlet domain of center $i \\in \\HQ^2$ or center $j \\in \\HQ^3$, we obtain a simple condition on the matrix entries of the side-pairing transformations of the fundamental domain of a Fuchsian or Kleinian group to be a DF-domain. Using the same methods, we also complement a result of Lakeland stating that a cofinite Fuchsian group has a DF domain (or a Dirichlet domain with multiple centers) if and only if it is an index $2$ subgroup of the discrete group G of reflections in a hyperbolic polygon.
J. Aragona, P. Catuogno, J. F. Colombeau, S. O. Juriaans, and Ch. Olivera
Springer Singapore
Adriana Alves, Giovanna de Souza Pereira, Valdecir de Assis Janasi, Michael Higgins, Liza Angelica Polo, Orlando Stanley Juriaans, and Bruno Vieira Ribeiro
Elsevier BV
S. O. Juriaans, A. De A. E Silva, and A. C. Souza Filho
Informa UK Limited
A conjecture due to Zassenhaus asserts that if G is a finite group then any torsion unit in ℤG is conjugate in ℚG to an element of G. Here, a weaker form of this conjecture is proved for some infinite groups.
J. Aragona, S. O. Juriaans, and J. F. Colombeau
American Mathematical Society (AMS)
In this paper we introduce Hausdorff locally convex algebra topologies on subalgebras of the whole algebra of nonlinear generalized functions. These topologies are strong duals of Frechet-Schwartz space topologies and even strong duals of nuclear Frechet space topologies. In particular any bounded set is relatively compact and one benefits from all deep properties of nuclearity. These algebras of generalized functions contain most of the classical irregular functions and distributions. They are obtained by replacing the mathematical tool of C∞ functions in the original version of nonlinear generalized functions by the far more evolved tool of holomorphic functions. This paper continues the nonlinear theory of generalized functions in which such locally convex topological properties were strongly lacking up to now.
E. Jespers, S. O. Juriaans, A. Kiefer, A. de A. e Silva, and A. C. Souza Filho
American Mathematical Society (AMS)
We give an algorithm to determine finitely many generators for a subgroup of finite index in the unit group of an integral group ring $\\mathbb{Z} G$ of a finite nilpotent group $G$, this provided the rational group algebra $\\mathbb{Q} G$ does not have simple components that are division classical quaternion algebras or two-by-two matrices over a classical quaternion algebra with centre $\\mathbb{Q}$. The main difficulty is to deal with orders in quaternion algebras over the rationals or a quadratic imaginary extension of the rationals. In order to deal with these we give a finite and easy implementable algorithm to compute a fundamental domain in the hyperbolic three space $\\mathbb{H}^3$ (respectively hyperbolic two space $\\mathbb{H}^2$) for a discrete subgroup of ${\\rm PSL}_2(\\mathbb{C})$ (respectively ${\\rm PSL}_2(\\mathbb{R})$) of finite covolume. Our results on group rings are a continuation of earlier work of Ritter and Sehgal, Jespers and Leal.
J. Aragona, J.F. Colombeau, and S.O. Juriaans
Elsevier BV
J. Aragona, A.R.G. Garcia, and S.O. Juriaans
Elsevier BV
S.O. Juriaans and A.C. Souza Filho
Elsevier BV
G. G. BASTOS, E. JESPERS, S. O. JURIAANS, and A. DE A. E SILVA
Cambridge University Press (CUP)
AbstractLet G be a group such that, for any subgroup H of G, every automorphism of H can be extended to an automorphism of G. Such a group G is said to be of injective type. The finite abelian groups of injective type are precisely the quasi-injective groups. We prove that a finite non-abelian group G of injective type has even order. If, furthermore, G is also quasi-injective, then we prove that G = K × B, with B a quasi-injective abelian group of odd order and either K = Q8 (the quaternion group of order 8) or K = Dih(A), a dihedral group on a quasi-injective abelian group A of odd order coprime with the order of B. We give a description of the supersoluble finite groups of injective type whose Sylow 2-subgroup are abelian showing that these groups are, in general, not quasi-injective. In particular, the characterisation of such groups is reduced to that of finite 2-groups that are of injective type. We give several restrictions on the latter. We also show that the alternating group A5 is of injective type but that the binary icosahedral group SL(2, 5) is not.
Jorge Aragona, Roseli Fernandez, Stanley O. Juriaans, and Michael Oberguggenberger
Springer Science and Business Media LLC
E. IWAKI, E. JESPERS, S. O. JURIAANS, and A. C. SOUZA FILHO
World Scientific Pub Co Pte Lt
In 1996, Jespers and Wang classified finite semigroups whose integral semigroup ring has finitely many units. In a recent paper, Iwaki–Juriaans–Souza Filho continued this line of research by partially classifying the finite semigroups whose rational semigroup algebra contains a ℤ-order with hyperbolic unit group. In this paper, we complete this classification and give an easy proof that deals with all finite semigroups.
S. O. Juriaans and J. R. Rogério
World Scientific Pub Co Pte Lt
We consider the problem of classifying those groups whose maximal cyclic subgroups are maximal. We give a complete classification of those groups with this property and which are either soluble or residually finite.
Jorge Aragona, Antônio Ronaldo Gomes Garcia, and Stanley Orlando Juriaans
Elsevier BV
Jorge Aragona, Roseli Fernandez, and Stanley O. Juriaans
Uniwersytet Mikolaja Kopernika/Nicolaus Copernicus University
We define intrinsic, natural and metrizable topologies
${\\mathcal T}_{\\Omega}$, ${\\mathcal T}$, ${\\mathcal T}_{s,\\Omega}$
and ${\\mathcal T}_s$ in ${\\mathcal G}(\\Omega)$, $\\OK$, ${\\mathcal G}_s(\\Omega)$
and $\\OK_s$, respectively. The topology ${\\mathcal T}_{\\Omega}$ induces
${\\mathcal T}$, ${\\mathcal T}_{s,\\Omega}$ and ${\\mathcal T}_s$.
The topologies ${\\mathcal T}_{s,\\Omega}$ and ${\\mathcal T}_s$
coincide with the Scarpalezos sharp topologies.
S. O. Juriaans, I. B. S. Passi, and A. C. Souza Filho
Springer Science and Business Media LLC
J. Aragona, S. O. Juriaans, O. R. B. Oliveira, and D. Scarpalezos
Cambridge University Press (CUP)
AbstractWe continue the investigation of the algebraic and topological structure of the algebra of Colombeau generalized functions with the aim of building up the algebraic basis for the theory of these functions. This was started in a previous work of Aragona and Juriaans, where the algebraic and topological structure of the Colombeau generalized numbers were studied. Here, among other important things, we determine completely the minimal primes of and introduce several invariants of the ideals of (Ω). The main tools we use are the algebraic results obtained by Aragona and Juriaans and the theory of differential calculus on generalized manifolds developed by Aragona and co-workers. The main achievement of the differential calculus is that all classical objects, such as distributions, become C∞-functions. Our purpose is to build an independent and intrinsic theory for Colombeau generalized functions and place them in a wider context.
E. Iwaki, S.O. Juriaans, and A.C. Souza Filho
Elsevier BV
E. Iwaki and S. O. Juriaans
Informa UK Limited
We classify groups G such that the unit group 𝒰 1(ℤ G) is hypercentral. In the second part, we classify groups G whose modular group algebra has hyperbolic unit groups 𝒰 1(KG).
Martin Hertweck, E Iwaki, Eric Jespers, and S. O Juriaans
Walter de Gruyter GmbH
Abstract For an arbitrary group G, and a G-adapted ring R (for example, R = ℤ), let 𝒰 be the group of units of the group ring RG, and let Z∞(𝒰) denote the union of the terms of the upper central series of 𝒰, the elements of which are called hypercentral units. It is shown that Z∞(𝒰) ⩽ (G). As a consequence, hypercentral units commute with all unipotent elements, and if G has non-normal finite subgroups with R(G) denoting their intersection, then [𝒰,Z∞(𝒰)] ⩽ R(G). Further consequences are given as well as concrete examples.
I. R. Hentzel, S. O. Juriaans, and L. A. Peresi
Informa UK Limited
Let F be an algebraically closed field of characteristic zero and L an RA loop. We prove that the loop algebra FL is in the variety generated by the split Cayley–Dickson algebra Z F over F. For RA2 loops of type M(Dih(A), −1,g 0), we prove that the loop algebra is in the variety generated by the algebra 𝒜 3 which is a noncommutative simple component of the loop algebra of a certain RA2 loop of order 16. The same does not hold for the RA2 loops of type M(G, −1,g 0), where G is a non-Abelian group of exponent 4 having exactly 2 squares.
J. Aragona, R. Fernandez, and S. O. Juriaans
Informa UK Limited
In this paper, we define natural and intrinsic metrizable topologies ℑΩ, ℑ s, Ω, ℑ and ℑ s on 𝒢(Ω), 𝒢 s (Ω), and , respectively. This allows us to speak of approximation and convergence in these algebras. The topologies induced by ℑΩ on 𝒢 s (Ω) and by ℑ on coincide with Scarpalezos's sharp topologies.