A Markov number is a specific type of positive integer that is associated with a particular solution to Markov's equation, which is given by: \[ x^2 + y^2 + z^2 = 3xyz \] where \( x \), \( y \), and \( z \) are positive integers. A set of numbers \( (x, y, z) \) that satisfies this equation is called a Markov triple.

Pell's equation is a specific type of Diophantine equation, which is an equation that seeks integer solutions. It is typically expressed in the form: \[ x^2 - Dy^2 = 1 \] Here, \( x \) and \( y \) are integers, and \( D \) is a positive integer that is not a perfect square. The main objective is to find integer pairs \((x, y)\) that satisfy this equation.

A **primitive Pythagorean triple** consists of three positive integers \( (a, b, c) \) that satisfy the equation \( a^2 + b^2 = c^2 \) and have a greatest common divisor (gcd) of 1, meaning they are coprime.

The Sum of Four Cubes Problem refers to the mathematical question of whether every integer can be expressed as the sum of four integer cubes.

Blind equalization is a signal processing technique used to improve the quality of received signals that have been distorted during transmission. It is particularly useful in communication systems where the characteristics of the channel (such as noise, interference, or distortion) are not known a priori. The term "blind" signifies that the equalization process does not require training signals or reference input to guide the adaptation of the equalizer.

Illés Relief is a type of relief sculpture characterized by its intricate details and craftsmanship. It refers to a specific artwork that depicts the biblical prophet Elijah (Illés in Hungarian) in a dramatic context, including scenes from his life and miracles. The relief captures the essence of the narrative and emotions associated with the prophet, often showcasing his encounters with nature and divine intervention.

Chronux is an open-source software toolbox used for analyzing neural data, particularly in the fields of neuroscience and neurophysiology. It is designed to facilitate the study of time series data, such as signals from brain electroencephalography (EEG), magnetoencephalography (MEG), and other related fields.

Cognitive hearing science is an interdisciplinary field that explores the relationship between hearing and cognitive processes, such as attention, memory, and language. It investigates how auditory information is processed, integrated, and interpreted in the brain, focusing on both the physiological aspects of hearing and the cognitive mechanisms involved in making sense of sounds.