Read More
Date: 17-6-2021
3271
Date: 3-8-2021
1459
Date: 8-5-2021
1731
|
A pathwise-connected domain is said to be simply connected (also called 1-connected) if any simple closed curve can be shrunk to a point continuously in the set. If the domain is connected but not simply, it is said to be multiply connected. In particular, a bounded subset of is said to be simply connected if both and , where denotes a set difference, are connected.
A space is simply connected if it is pathwise-connected and if every map from the 1-sphere to extends continuously to a map from the 2-disk. In other words, every loop in the space is contractible.
REFERENCES:
Croft, H. T.; Falconer, K. J.; and Guy, R. K. Unsolved Problems in Geometry. New York: Springer-Verlag, p. 2, 1991.
Krantz, S. G. Handbook of Complex Variables. Boston, MA: Birkhäuser, p. 27, 1999.
|
|
مخاطر عدم علاج ارتفاع ضغط الدم
|
|
|
|
|
اختراق جديد في علاج سرطان البروستات العدواني
|
|
|
|
|
مدرسة دار العلم.. صرح علميّ متميز في كربلاء لنشر علوم أهل البيت (عليهم السلام)
|
|
|