4 papers
Caterpillar trees are asymmetric, balanced trees are symmetric
Kalle Leppälä
Two conjectures of Allman, Long and Rhodes are proven. The ultrametric exchangeable model captures the symmetries in allele distributions of ultrametric mechanistic models of coale…
Rational approximations of the exponential function at rational points
Kalle Leppälä, Tapani Matala-aho, Topi Törmä
We give explicit and asymptotic lower bounds for the quantity by studying a generalized continued fraction expansion of . In cases we improve e…
On irrationality exponents of generalized continued fractions
Jaroslav Hancl, Kalle Leppälä, Tapani Matala-aho +1
We study how the asymptotic irrationality exponent of a given generalized continued fraction \[ \K_{n=1}^\infty \frac{a_n}{b_n}\,,\quad a_n, b_n\in \mathbb{Z}^+, \] behaves as a fu…
An explicit Baker type lower bound of exponential values
Anne-Maria Ernvall-Hytönen, Kalle Leppälä, Tapani Matala-aho
Let denote an imaginary quadratic field or the field of rational numbers and its ring of intergers. We shall prove an explicit B…