Ozlem Ejder

activity

20162026

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5 papers · 1 filter

math.NT2026

Arboreal Galois Groups of a PCF Map with Strictly Pre-periodic Critical Points

Özlem Ejder, Zofia Gołaska, Yasemin Kara +2

We study the arithmetic and geometric iterated monodromy groups associated to the postcritically finite (PCF) quadratic rational function $f (x) = \frac{2}{( x - 1 ) ^{2}}$ defined over a nu…

math.NT2025

Rational isolated $j$ -invariants from $X_{1} (ℓ^{n})$ and $X_{0} (ℓ^{n})$

Abbey Bourdon, Özlem Ejder

Let $ℓ$ and $n$ be positive integers with $ℓ$ prime. The modular curves $X_{1} (ℓ^{n})$ and $X_{0} (ℓ^{n})$ are algebraic curves over $Q$ whose non-cuspidal points param…

math.NT2022

Isolated Points on $X_{1} (ℓ^{n})$ with rational $j$ -invariant}

Ozlem Ejder

Let $ℓ$ be a prime and let $n \geq 1$ . In this note we show that if there is a non-cuspidal, non-CM isolated point $x$ with a rational $j$ -invariant on the modular curve $X_1(\el…

math.NT2018

On the level of modular curves that give rise to isolated $j$ -invariants

Abbey Bourdon, Ozlem Ejder, Yuan Liu +2

We say a closed point $x$ on a curve $C$ is sporadic if $C$ has only finitely many closed points of degree at most $deg (x)$ and that $x$ is isolated if it is not in…

math.NT2016

Monodromy of Fermat Surfaces and Modular Symbols for Fermat curves

Ozlem Ejder

Let $F_{n}$ denote the Fermat curve given by $x^{n} + y^{n} = z^{n}$ and let $μ_{n}$ denote the Galois module of $n$ th roots of unity. It is known that the integral homology group $H_{1} (F_{n}, Z)$ …

Arboreal Galois Groups of a PCF Map with Strictly Pre-periodic Critical Points

Rational isolated j-invariants from X1​(ℓn) and X0​(ℓn)

Isolated Points on X1​(ℓn) with rational j-invariant}

On the level of modular curves that give rise to isolated j-invariants

Monodromy of Fermat Surfaces and Modular Symbols for Fermat curves

Rational isolated $j$ -invariants from $X_{1} (ℓ^{n})$ and $X_{0} (ℓ^{n})$

Isolated Points on $X_{1} (ℓ^{n})$ with rational $j$ -invariant}

On the level of modular curves that give rise to isolated $j$ -invariants