The Palais–Smale compactness condition is a criterion used in the context of variational methods and critical point theory, particularly when dealing with the analysis of functionals on Banach spaces or Hilbert spaces. It plays a crucial role in the study of minimization problems and the existence of critical points.

The Weierstrass–Erdmann conditions are a set of necessary conditions that must be satisfied by the trajectories of optimal control problems at points where the control switches from one value to another. These conditions arise in the context of the calculus of variations and optimal control theory when dealing with piecewise continuous controls.

Calendrical calculations refer to the mathematical methods and algorithms used to compute calendar dates, determine the day of the week for any given date, and perform conversions between different calendar systems. This area of study encompasses various aspects, including: 1. **Date Calculations**: Determining the difference between two dates, calculating future or past dates by adding or subtracting days, months, or years, and understanding leap years.

The date of Easter varies each year because it is determined based on a lunar calendar. Easter is celebrated on the first Sunday after the first full moon following the vernal equinox (around March 21). This means that Easter can fall anywhere between March 22 and April 25. For specific years, here are the dates for Easter in the near future: - In 2024, Easter will be on March 31.

Dodecatemoria, also known as the "Dodecatemoria of the Tetraktys," is a concept in ancient Greek philosophy, particularly associated with Pythagorean thought. The term itself is derived from the Greek words "dodeca," meaning twelve, and "temoria," referring to divisions or parts.

A Julian day is a continuous count of days since the beginning of the Julian period, which is defined to start at noon Universal Time (UTC) on January 1, 4713 BC in the proleptic Julian calendar. This system of timekeeping was introduced by the French scholar Joseph Scaliger in 1583 and is used primarily by astronomers to avoid the complications of calendar systems that can vary in length and structure.

Henri Hogbe Nlend was a prominent Cameroonian politician and historian who played a significant role in Cameroon's post-independence politics. He is known for his contributions to the understanding of Cameroon's history and politics, particularly regarding the country's transition from colonial rule to independence. He was involved in the political scene during the period of decolonization in Africa and engaged with various political movements and parties within Cameroon.

André Larivière is a name that may refer to various individuals, depending on the context. Without additional details, it's challenging to pinpoint a specific person. If you are referring to a notable figure in art, science, politics, or another field, could you provide more context or specify the area you are interested in?

Gordon Edwards is a Canadian physicist and noted critic of nuclear power. He is particularly known for his work on the health and environmental impacts of nuclear energy and for his advocacy for alternative energy sources. Edwards has been involved in public education and activism, focusing on issues related to nuclear safety, radioactive waste management, and the risks associated with nuclear reactors. He has also contributed to various discussions and publications regarding the dangers of nuclear power and has been a prominent figure in the anti-nuclear movement in Canada.

Jim Bohlen is best known as an environmental activist and one of the co-founders of the organization Greenpeace. He played a significant role in raising awareness about environmental issues, particularly relating to nuclear testing and the protection of the environment. Bohlen was part of the group that organized the first Greenpeace mission in 1971 to prevent nuclear testing in Alaska. His activism contributed to the growth of the global environmental movement.

Metta Spencer is a noted sociologist, peace researcher, and advocate for nonviolent conflict resolution. She has made significant contributions to the study of social movements, peace studies, and the dynamics of conflict. Spencer is known for her work on understanding the roles of social relationships and dialogue in promoting peace and resolving conflicts. She has also been involved in various academic and public discussions on issues related to peace, ethics, and social change.

"Discoveries" by Jack B. Child is likely a work that explores various themes related to knowledge, exploration, and the human experience. However, I don't have specific information on a book by that title or author in my training data. Jack B. Child is known for his involvement in education and possibly writing in the fields of history or cultural studies. If "Discoveries" pertains to a specific topic within those areas, it may address significant historical findings or their impacts on society.

Quantum affine algebras are a class of mathematical objects that arise in the area of quantum algebra, which blends concepts from quantum mechanics and algebraic structures. To understand quantum affine algebras, it's helpful to break down the components involved: 1. **Affine Algebras**: These are a type of algebraic structure that generalize finite-dimensional Lie algebras. An affine algebra can be thought of as an infinite-dimensional extension of a Lie algebra, which incorporates the concept of loops.

Canadian mathematicians have made significant contributions to the field across various centuries. Here's a brief overview of some notable mathematicians by century: ### 19th Century - **Évariste Galois** (1811-1832): Although not Canadian himself, his work influenced many mathematicians in Canada, particularly those involved in algebra and group theory.

Canadian women mathematicians have made significant contributions to various fields within mathematics, often overcoming barriers in a historically male-dominated discipline. Some notable figures include: 1. **Mina Andrew** - Known for her work in topology and mathematical education. 2. **Wendy Myrvold** - A prominent figure in combinatorial design and graph theory. 3. **Lisa Charline** - A researcher recognized for her contributions in algebra and number theory.

As of my last update in October 2021, Aleksandar Nikolov is a computer scientist known for his work in theoretical computer science, particularly in the fields of algorithms, machine learning, and complexity theory. He has contributed to various areas, including the development of algorithms for optimization problems and advancements in understanding machine learning from a theoretical perspective.

Anne Broadbent is a researcher known for her work in psychology and cognitive science. She has made contributions to the field, particularly in areas related to attention, perception, and social cognition. More specific details about her research or professional background may depend on particular publications or roles she has held.

Arthur Preston Mellish does not appear to be a widely recognized public figure or concept based on available information up to October 2023. It's possible that he may be a private individual, a historical figure of local significance, or a fictional character that is not extensively documented in popular sources.

Arthur Stanley Mackenzie was a British mathematician known for his work in the field of mathematics and physics. He contributed to various areas, including differential equations and mathematical physics.

As of my last update in October 2023, "Brian Marcus" does not refer to a widely known figure or entity that would be identifiable in popular culture, history, or specific fields. There may be many individuals with that name across various professions and contexts.