Characterizations of some bitopological separation axioms in terms of $ij - \theta $ - closure operator

S. K. Sen; J. N. Nandi; M. N. Mukherjee

Displaying similar documents to “Characterizations of some bitopological separation axioms in terms of $i j - θ$ - closure operator”

$T_{i}$ - pairwise continuous functions and bitopological separation axioms

M. Jelić (1989)

Matematički Vesnik

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Axioms weaker then $R_{0}$

J. Guia (1984)

Matematički Vesnik

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The $S_{α}$ separation axioms

J. Guia (1986)

Matematički Vesnik

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On geodesics of phyllotaxis

Roland Bacher (2014)

Confluentes Mathematici

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Seeds of sunflowers are often modelled by $n ⟼ ϕ_{θ} (n) = \sqrt{n} e^{2 i π n θ}$ leading to a roughly uniform repartition with seeds indexed by consecutive integers at angular distance $2 π θ$ for $θ$ the golden ratio. We associate to such a map $ϕ_{θ}$ a geodesic path $γ_{θ} : ℝ_{> 0} ⟶ {PSL}_{2} (ℤ) ∖ ℍ$ of the modular curve and use it for local descriptions of the image $ϕ_{θ} (ℕ)$ of the phyllotactic map $ϕ_{θ}$ .

Some remarks on the interpolation spaces $A^{θ}, A_{θ}$

Mohammad Daher (2016)

Commentationes Mathematicae Universitatis Carolinae

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Let $(A_{0}, A_{1})$ be a regular interpolation couple. Under several different assumptions on a fixed $A^{β}$ , we show that $A^{θ} = A_{θ}$ for every $θ \in (0, 1)$ . We also deal with assumptions on ${\bar{A}}^{β}$ , the closure of $A^{β}$ in the dual of ${(A_{0}^{*}, A_{1}^{*})}_{β}$ .

A classification scheme for axioms weaker than $T_{0}$

G. Ervynck (1991)

Matematički Vesnik

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Linearly-invariant families and generalized Meixner–Pollaczek polynomials

Iwona Naraniecka, Jan Szynal, Anna Tatarczak (2013)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

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The extremal functions $f_{0} (z)$ realizing the maxima of some functionals (e.g. $max | a_{3} |$ , and $max a r g f^{^{'}} (z)$ ) within the so-called universal linearly invariant family $U_{α}$ (in the sense of Pommerenke [10]) have such a form that $f_{0}^{^{'}} (z)$ looks similar to generating function for Meixner-Pollaczek (MP) polynomials [2], [8]. This fact gives motivation for the definition and study of the generalized Meixner-Pollaczek (GMP) polynomials $P_{n}^{λ} (x; θ, ψ)$ of a real variable $x$ as coefficients of $G^{λ} (x; θ, ψ; z) = \frac{1}{{(1 - z e^{i θ})}^{λ - i x} {(1 - z e^{i ψ})}^{λ + i x}} = \sum_{n = 0}^{\infty} P_{n}^{λ} (x; θ, ψ) z^{n}, | z | < 1,$ where the parameters $λ$ , $θ$ , $ψ$ satisfy the conditions:...

Compatibility of the theta correspondence with the Whittaker functors

Vincent Lafforgue, Sergey Lysenko (2011)

Bulletin de la Société Mathématique de France

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We prove that the global geometric theta-lifting functor for the dual pair $(H, G)$ is compatible with the Whittaker functors, where $(H, G)$ is one of the pairs $({S 𝕆}_{2 n}, {𝕊 p}_{2 n})$ , $({𝕊 p}_{2 n}, {S 𝕆}_{2 n + 2})$ or $({𝔾 L}_{n}, {𝔾 L}_{n + 1})$ . That is, the composition of the theta-lifting functor from $H$ to $G$ with the Whittaker functor for $G$ is isomorphic to the Whittaker functor for $H$ .

Singularities of $2 Θ$ -divisors in the jacobian

Christian Pauly, Emma Previato (2001)

Bulletin de la Société Mathématique de France

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We consider the linear system $| 2 Θ_{0} |$ of second order theta functions over the Jacobian $J C$ of a non-hyperelliptic curve $C$ . A result by J.Fay says that a divisor $D \in | 2 Θ_{0} |$ contains the origin $𝒪 \in J C$ with multiplicity $4$ if and only if $D$ contains the surface $C - C = {𝒪 (p - q) ∣ p, q \in C} \subset J C$ . In this paper we generalize Fay’s result and some previous work by R.C.Gunning. More precisely, we describe the relationship between divisors containing $𝒪$ with multiplicity $6$ , divisors containing the fourfold $C_{2} - C_{2} = {𝒪 (p + q - r - s) ∣ p, q, r, s \in C}$ , and divisors singular along $C - C$ , using...

On the Set-Theoretic Strength of Countable Compactness of the Tychonoff Product $2^{ℝ}$

Eleftherios Tachtsis (2010)

Bulletin of the Polish Academy of Sciences. Mathematics

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We work in ZF set theory (i.e., Zermelo-Fraenkel set theory minus the Axiom of Choice AC) and show the following: 1. The Axiom of Choice for well-ordered families of non-empty sets ( $A C^{W O}$ ) does not imply “the Tychonoff product $2^{ℝ}$ , where 2 is the discrete space 0,1, is countably compact” in ZF. This answers in the negative the following question from Keremedis, Felouzis, and Tachtsis [Bull. Polish Acad. Sci. Math. 55 (2007)]: Does the Countable Axiom of Choice for families of non-empty sets...

Essentially Incomparable Banach Spaces of Continuous Functions

Rogério Augusto dos Santos Fajardo (2010)

Bulletin of the Polish Academy of Sciences. Mathematics

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We construct, under Axiom ♢, a family ${(C (K_{ξ}))}_{ξ < 2^{(2^{ω})}}$ of indecomposable Banach spaces with few operators such that every operator from $C (K_{ξ})$ into $C (K_{η})$ is weakly compact, for all ξ ≠ η. In particular, these spaces are pairwise essentially incomparable. Assuming no additional set-theoretic axiom, we obtain this result with size $2^{ω}$ instead of $2^{(2^{ω})}$ .

Comments on the fractional parts of Pisot numbers

Toufik Zaïmi, Mounia Selatnia, Hanifa Zekraoui (2015)

Archivum Mathematicum

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Let $L (θ, λ)$ be the set of limit points of the fractional parts ${λ θ^{n}}$ , $n = 0, 1, 2, \dots$ , where $θ$ is a Pisot number and $λ \in ℚ (θ)$ . Using a description of $L (θ, λ)$ , due to Dubickas, we show that there is a sequence ${(λ_{n})}_{n \geq 0}$ of elements of $ℚ (θ)$ such that $Card (L (θ, λ_{n})) < Card (L (θ, λ_{n + 1}))$ , $\forall$ $n \geq 0$ . Also, we prove that the fractional parts of Pisot numbers, with a fixed degree greater than 1, are dense in the unit interval.

On weakly $θ$ -continuous functions

F. Commaroto, T. Noiri (1986)

Matematički Vesnik

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$ℰ_{B}$ -dimension function of bitopological spaces

M. Jelić (1987)

Matematički Vesnik

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The CR Yamabe conjecture the case $n = 1$

Najoua Gamara (2001)

Journal of the European Mathematical Society

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Let $(M, θ)$ be a compact CR manifold of dimension $2 n + 1$ with a contact form $θ$ , and $L = (2 + 2 / n) Δ_{b} + R$ its associated CR conformal laplacien. The CR Yamabe conjecture states that there is a contact form $\tilde{θ}$ on $M$ conformal to $θ$ which has a constant Webster curvature. This problem is equivalent to the existence of a function $u$ such that $L u = u^{1 + 2 / n}$ , $u > 0$ on $M$ . D. Jerison and J. M. Lee solved the CR Yamabe problem in the case where $n \geq 2$ and $(M, θ)$ is not locally CR equivalent to the sphere $S^{2 n + 1}$ of $𝐂^{n}$ . In a join work with R. Yacoub, the CR Yamabe...

Sums of Three Prime Squares

Hiroshi Mikawa, Temenoujka Peneva (2007)

Bollettino dell'Unione Matematica Italiana

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Let $A,\epsilon>0$ be arbitrary. Suppose that $x$ is a sufficiently large positive number. We prove that the number of integers $n\in(x,x+x^{\theta}]$ , satisfying some natural congruence conditions, which cannot be written as the sum of three squares of primes is $\ll x^{\theta}(\log x)^{-A}$ , provided that $\frac{7}{16}+\epsilon\leq\theta\leq 1$ .

Singularities of theta divisors and the geometry of $𝒜_{5}$

Gavril Farkas, Samuele Grushevsky, Salvati R. Manni, Alessandro Verra (2014)

Journal of the European Mathematical Society

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We study the codimension two locus $H$ in $𝒜_{g}$ consisting of principally polarized abelian varieties whose theta divisor has a singularity that is not an ordinary double point. We compute the class $[H] \in C H^{2} (𝒜_{g})$ for every $g$ . For $g = 4$ , this turns out to be the locus of Jacobians with a vanishing theta-null. For $g = 5$ , via the Prym map we show that $H \subset 𝒜_{5}$ has two components, both unirational, which we describe completely. We then determine the slope of the effective cone of $\bar{𝒜_{5}}$ and show that the component $\bar{N_{0}^{'}}$ of the Andreotti-Mayer...

Displaying similar documents to “Characterizations of some bitopological separation axioms in terms of i j - θ - closure operator”

Displaying similar documents to “Characterizations of some bitopological separation axioms in terms of $i j - θ$ - closure operator”