Braeburn of sweet and tart flavour. They are available October through April in the northern hemisphere and are medium to large in size. They are a popular fruit for growers because of their ability to store well when chilled. Braeburn apples are useful in cooking in that they hold their shape and do not release a great deal of liquid making them ideal for tarts. According to the US Apple Association website it is one of the fifteen most popular apple cultivars in the United States. Apples can be preserved by short, medium or long-term storage. Braeburn can turn brown inside
History of manifolds and varieties History of manifolds and varieties The study of manifolds combines many important areas of mathematics: it generalizes concepts such as curves and surfaces as well as ideas from linear algebra and topology. Certain special classes of manifolds also have additional algebraic structure; they may behave like groups, for instance. In that case, they are called Lie Groups. Alternatively, they may be described by polynomial equations, in which case they are called algebraic varieties, and if they additionally carry a group structure, they are called algebraic groups. The term "manifold" comes from German "Mannigfaltigkeit," by Riemann. In English, "manifold" refers to