By Gracia-Bondia J.M., Varilly J.C., Figueroa H.
ISBN-10: 1421451492
ISBN-13: 9781421451497
ISBN-10: 1731752113
ISBN-13: 9781731752116
ISBN-10: 1751811913
ISBN-13: 9781751811916
ISBN-10: 2402483113
ISBN-13: 9782402483117
ISBN-10: 2512672824
ISBN-13: 9782512672821
ISBN-10: 2603714104
ISBN-13: 9782603714102
The topic of this article is an algebraic and operatorial transforming of geometry, which lines its roots to quantum physics; Connes has proven that noncommutative geometry retains all crucial positive aspects of the metric geometry of manifolds. Many singular areas that emerge from advances in arithmetic or are utilized by physicists to appreciate the flora and fauna are thereby introduced into the world of geometry. "This publication is an advent to the language and methods of noncommutative geometry at a degree compatible for graduate scholars, and in addition presents enough element to be helpful to physicists and mathematicians wishing to go into this quickly growing to be box. it will probably additionally function a reference textual content on numerous subject matters which are appropriate to noncommutative geometry.
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This is often the 3rd released quantity of the lawsuits of the Israel Seminar on Geometric facets of sensible research. the big majority of the papers during this quantity are unique study papers. there has been final yr a robust emphasis on classical finite-dimensional convexity idea and its reference to Banach house thought.
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Example text
T♦ t❤❡ ❝✉r✈❡ ♦r s✉r❢❛❝❡ ❡q✉❛t✐♦♥s✳ Hermite interpolation ■♥ ❍❡r♠✐t❡ ✐♥t❡r♣♦❧❛t✐♦♥✱ ✇❡ ❞✐✛❡r❡♥t✐❛t❡ t❤❡ ❡q✉❛t✐♦♥s ♦❢ t❤❡ ❝✉r✈❡ ♦r s✉r❢❛❝❡✱ ❛♥❞ s♦❧✈❡ s✐♠✉❧t❛♥❡♦✉s ❡q✉❛t✐♦♥s ❢♦r ❜♦t❤ ♣♦s✐t✐♦♥ ❛♥❞ t❛♥❣❡♥t ✈❛❧✉❡ ❛t ❡❛❝❤ ♦❢ t❤❡ ♣♦✐♥ts ❜❡✐♥❣ ✐♥t❡r♣♦❧❛t❡❞✳ ❚❤✉s t✇✐❝❡ ❛s ♠❛♥② ❝♦❡✣❝✐❡♥ts ❛r❡ r❡q✉✐r❡❞ ❛s ✐♥ t❤❡ ▲❛❣r❛♥❣❡ ❝❛s❡✳ ❆ ♣❛r✲ t✐❝✉❧❛r❧② ✐♠♣♦rt❛♥t ❝❛s❡ ✐s ❝♦♥str✉❝t✐♥❣ ❛ ❝✉r✈❡ ❜❡t✇❡❡♥ t✇♦ ❡♥❞ ■♥t❡r♣♦❧❛t✐♦♥ ✸✺ ✸✭✐✮✖▲❛❣r❛♥❣❡ ❛♥❞ ❍❡r♠✐t❡ ✐♥t❡r♣♦❧❛t✐♦♥ ✉s❡❞ t♦ ❝♦♥✲ str✉❝t ❛ ♣❛r❛♠❡tr✐❝ ❝✉❜✐❝ ❝✉r✈❡ s❡❣♠❡♥t✳ ♣♦✐♥ts✱ ✇✐t❤ ❦♥♦✇♥ t❛♥❣❡♥t ✈❛❧✉❡s ❛t ❡❛❝❤✳ ❚❤❛t r❡q✉✐r❡s ❛ ❝✉r✈❡ ✇✐t❤ ❢♦✉r ❝♦❡✣❝✐❡♥ts ✐♥ ❡❛❝❤ ❡q✉❛t✐♦♥✱ ✇❤✐❝❤ ❛r❡ ❝✉❜✐❝s ❀ t❤❡r❡ ✐s ❛❧s♦ ❛♥ ❡q✉✐✈❛❧❡♥t ♣❛t❝❤ ✇❤✐❝❤ r✉♥s ❜❡t✇❡❡♥ ❢♦✉r ❝♦r♥❡r ♣♦✐♥ts✱ ❛♥❞ ❤❛s ✶✻ ❝♦❡✣❝✐❡♥ts✳ ❈✉❜✐❝s ❛r❡ ❢r❡q✉❡♥t s✐❣❤t✐♥❣s ✐♥ ❝♦♠♣✉t✐♥❣ ✇✐t❤ ❣❡♦♠❡tr②✿ s❡❡ ■❧❧✉str❛t✐♦♥ ✸✭✐✮✳ The problem of parameterization ■♥t❡r♣♦❧❛t✐♥❣ ♣❛r❛♠❡tr✐❝ ❝✉r✈❡s✱ ❞❡❝✐❞✐♥❣ ✇❤❛t t❤❡ ♣❛r❛♠❡t❡r ✈❛❧✲ ✉❡s ❛t ❡❛❝❤ ♣♦✐♥t ✇✐❧❧ ❜❡✖t❤❡ ✐ss✉❡ ♦❢ ♣❛r❛♠❡t❡r✐③❛t✐♦♥✖✐s ❝r✉❝✐❛❧✳ ✭❚❤❛t ✐s ❛ ♣r♦❜❧❡♠ t❤❛t ❞♦❡s ♥♦t ♦❝❝✉r ✇✐t❤ ❡①♣❧✐❝✐t✱ s✐♥❣❧❡✲✈❛❧✉❡❞✱ ❝✉r✈❡s ❛♥❞ s✉r❢❛❝❡s✿ ❛♥❞ s♦ ✇❡ ❝❛♥ s❡❡ ✇❤② t❤❡s❡ ❛r❡ ♣r❡❢❡rr❡❞ ❢♦r ❞r❛✇✐♥❣ ❣r❛♣❤s ❛♥❞ s♦ ♦♥✳ ❆♥❞ t❡❝❤♥✐q✉❡s ❢r♦♠ ❵❣r❛♣❤✐♥❣✬ ❛♣♣❧✐❝❛✲ t✐♦♥s ✉s✉❛❧❧② ❡①♣❧♦✐t t❤✐s ❧✐♠✐t❛t✐♦♥✱ ✇❤✐❝❤ ✐s ✇❤② ✇❡ s❤♦✉❧❞ ❜❡ ✇❛r② ♦❢ tr②✐♥❣ t♦ tr❛♥s♣❧❛♥t t❤❡♠ t♦ ♠♦r❡ ❣❡♥❡r❛❧ ❣❡♦♠❡tr✐❝ ♣r♦❜❧❡♠s✳✮ ❙♦✱ t❤❡ ♣r♦❜❧❡♠ ✇✐t❤ ✐♥t❡r♣♦❧❛t✐♥❣ ♣❛r❛♠❡tr✐❝ ❝✉r✈❡s ✐s t❤❛t✱ ✇❤✐❧❡ t❤❡ ♣♦s✐t✐♦♥s ❛♥❞ t❛♥❣❡♥t ❞✐r❡❝t✐♦♥s ♠❛② ❜❡ ♣r♦✈✐❞❡❞✱ ✇❡ ❤❛✈❡ t♦ ❡st✐♠❛t❡ t❤❡ ♣❛r❛♠❡t❡r ✈❛❧✉❡s t❤❛t t❤❡ ❝✉r✈❡ ❵s❤♦✉❧❞✬ ❤❛✈❡ ✇❤❡♥ ✐t ♣❛ss❡s ❡❛❝❤ ♣♦✐♥t✱ ❛♥❞ t❤❡ ♠❛❣♥✐t✉❞❡ ❛s ✇❡❧❧ ❛s ❞✐r❡❝t✐♦♥ ♦❢ ❞❡r✐✈❛✲ t✐✈❡s✳ ■♥ t❤❡ ❝❛s❡ ♦❢ ▲❛❣r❛♥❣❡ ✐♥t❡r♣♦❧❛t✐♦♥✱ t❤❡ s✐♠♣❧❡st ❝❤♦✐❝❡ ✐s t♦ s♣❛❝❡ ♣❛r❛♠❡tr✐❝ ✈❛❧✉❡s ❡q✉❛❧❧② ❜❡t✇❡❡♥ ♣♦✐♥t ❞❛t❛✳ ❚❤✐s ✇♦r❦s ✐❢ t❤❡ ♣♦✐♥ts ❛r❡ t❤❡♠s❡❧✈❡s q✉✐t❡ ❡✈❡♥❧② s♣❛❝❡❞❀ ♦t❤❡r✇✐s❡ s♦♠❡✲ t❤✐♥❣ ❜❡tt❡r ✐s ♥❡❡❞❡❞✳ ❙✐♥❝❡ ♣❛r❛♠❡t❡r✐③❛t✐♦♥ ✐s r❡❧❛t❡❞ t♦ ❝✉r✈❡ ❛r❛♠❡tr✐❝ ❝✉r✈❡s ❛♥❞ s✉r❢❛❝❡s ✸✻ ❧❡♥❣t❤✱ ✇❡ ✇♦✉❧❞ ❧✐❦❡ t♦ ❦♥♦✇ ✇❤❛t t❤❡ ❧❡♥❣t❤ ♦❢ t❤❡ ❝✉r✈❡ ✇✐❧❧ ❜❡ ❜❡t✇❡❡♥ ❡❛❝❤ ❞❛t❛ ♣♦✐♥t❀ ❜✉t t❤❛t ✐s ♣✉tt✐♥❣ t❤❡ ❝❛rt ❜❡❢♦r❡ t❤❡ ❤♦rs❡✱ ❜❡❝❛✉s❡ ✇❡ ❤❛✈❡♥✬t ❣♦t t❤❡ ❝✉r✈❡ ②❡t✳ ❖♥❡ ❝♦✉❧❞ ✐♠♣❧❡♠❡♥t ❛ t❡❝❤♥✐q✉❡ ♦❢ s✉❝❝❡ss✐✈❡ r❡✜♥❡♠❡♥t✖s❡t ✉♣ ♦♥❡ ❝✉r✈❡✱ ❣❡t t❤❡ ❝✉r✈❡ ❧❡♥❣t❤s ❢r♦♠ ✐t✱ ❛♥❞ t❤✉s ♦❜t❛✐♥ ♥❡✇ ♣❛r❛♠❡t❡r ✈❛❧✉❡s ❛t t❤❡ ❞❛t❛ ♣♦✐♥ts✱ ❛♥❞ r❡♣❡❛t t❤❡ ❡①❡r❝✐s❡✖❜✉t t❤✐s r✐❣♠❛r♦❧❡ ✐s ♥♦t ✉s✉❛❧❧② ❛t✲ t❡♠♣t❡❞❀ ✐t ✇♦✉❧❞ ♣r♦❜❛❜❧② ❜❡ ❞✐✣❝✉❧t ❡✈❡♥ t♦ ♣r♦✈❡ t❤❛t ✐t ✇♦✉❧❞ ❝♦♥✈❡r❣❡✳ ❚❤❡ ✉s✉❛❧ s♦❧✉t✐♦♥ ✐s ❝❤♦r❞✲❧❡♥❣t❤ ♣❛r❛♠❡t❡r✐③❛t✐♦♥✱ ✇❤❡r❡ t❤❡ ♣❛r❛♠❡t❡r ✈❛❧✉❡s ❛t t❤❡ ♣♦✐♥ts ❛r❡ ❜❛s❡❞ ♦♥ t❤❡ ❧❡♥❣t❤s ♦❢ t❤❡ str❛✐❣❤t✲❧✐♥❡ s❡❣♠❡♥ts ❝♦♥♥❡❝t✐♥❣ t❤❡♠✳ ❚❤✐s ✐s ❛ ❣♦♦❞ ✇♦r❦❤♦rs❡✱ ❣✐✈✐♥❣ tr♦✉❜❧❡ ♦♥❧② ✇❤❡♥ t❤❡r❡ ❛r❡ ❛❜r✉♣t ❵❝♦r♥❡rs✬ ✐♠♣❧✐❡❞ ❜② t❤❡ ❞❛t❛✱ ❛♥❞ ❝❤❛♥❣❡s ♦❢ s♣❛❝✐♥❣✳ ❋✉rt❤❡r r❡✜♥❡♠❡♥ts ✐♥✈♦❧✈❡ t❛❦✐♥❣ t❤❡ ❛♥❣❧❡ ❜❡t✇❡❡♥ s✉❝❝❡ss✐✈❡ s♣❛♥s ✐♥t♦ ❛❝❝♦✉♥t ✭s❡❡ ❋❛r✐♥✬s ❜♦♦❦ ❈✉r✈❡s ❛♥❞ ❙✉r❢❛❝❡s ❢♦r ❈♦♠♣✉t❡r ❆✐❞❡❞ ●❡♦♠❡tr✐❝ ❉❡s✐❣♥ ❢♦r ♠♦r❡ ❞❡t❛✐❧✮✳ ❲✐t❤ ❍❡r♠✐t❡ ✐♥t❡r♣♦❧❛t✐♦♥✱ s✐♠✐❧❛r ♣r♦❜❧❡♠s ♦❝❝✉r❀ ❛♥❞ ✐t ♠✉st ❜❡ r❡♠❡♠❜❡r❡❞ t❤❛t ♠❛❣♥✐t✉❞❡s ♦❢ ❞❡r✐✈❛t✐✈❡s ♦❢ t❤❡ ❢♦r♠ dx dt ❡t❝✳✱ ❛r❡ r❡❧❛t❡❞ t♦ t❤❡ ❛❝t✉❛❧ s✐③❡ ♦❢ t❤❡ ❝✉r✈❡ ✐♥ t❤❡ ✉♥✐ts ♦❢ ❧❡♥❣t❤ ❜❡✐♥❣ ✉s❡❞✳ ❚❤✉s✱ ✐❢ ✇❡ s❝❛❧❡ ❛ ❝✉r✈❡ ❜② s❝❛❧✐♥❣ t❤❡ ✈❛❧✉❡s ♦❢ ✐ts ❍❡r♠✐t❡ ❝♦❡✣❝✐❡♥ts✱ ✇❡ ♠✉st s❝❛❧❡ t❤❡ ❞❡r✐✈❛t✐✈❡s ❡①♣❧✐❝✐t❧②✳ ❚❤❛t✬s ❡❛s② ❡♥♦✉❣❤ ❢♦r ❛ s✐♠♣❧❡ s❝❛❧✐♥❣✱ ❜✉t ✇❤❛t ❛❜♦✉t ❛ s❤❡❛r tr❛♥s❢♦r♠❄ ❆❧❧ t❤❡s❡ r❡♠❛r❦s ❤❛✈❡ ❜❡❡♥ ❛❞❞r❡ss❡❞ t♦ t❤❡ ♣r♦❜❧❡♠ ♦❢ ✐♥t❡r✲ ♣♦❧❛t✐♦♥✱ ❜✉t ❛❧s♦ ❛♣♣❧② t♦ ❝✉r✈❡ ✜tt✐♥❣✳ ❆❣❛✐♥✱ t❤✐s ✐s ❛ ♣r♦❝❡ss t❤❛t ✇♦r❦s ✇❡❧❧ ✇✐t❤ ❡①♣❧✐❝✐t ❣❡♦♠❡tr②✱ ❛♥❞ ❢❛✐r❧② ✇❡❧❧ ✇✐t❤ ✐♠♣❧✐❝✲ ✐ts ✭❡①❝❡♣t t❤❛t ♥♦r♠❛❧✐③❛t✐♦♥ ❝❛✉s❡s ❛ ♣r♦❜❧❡♠✮✳ ❲✐t❤ ♣❛r❛♠❡tr✐❝ ❣❡♦♠❡tr②✱ ✇❡ ❛❣❛✐♥ ❤❛✈❡ t♦ ❞❡❝✐❞❡ ✐♥ ❛❞✈❛♥❝❡ ✇❤❛t ♣❛r❛♠❡t❡r ✈❛❧✉❡ ❡❛❝❤ ♣♦✐♥t ✇✐❧❧ ❝♦rr❡s♣♦♥❞ t♦✳ ❇✉t ✐❢ t❤❡ ♣♦✐♥ts ❛r❡ ❛t ❛❧❧ ❞❡♥s❡✱ t❤✐s ✐s ❞✐✣❝✉❧t✿ ❝❤♦r❞✲❧❡♥❣t❤ ♣❛r❛♠❡t❡r✐③❛t✐♦♥ ✐s ❝❡rt❛✐♥❧② ✉s❡❧❡ss✳ ❲❡ ❝♦♥❝❧✉❞❡ t❤✐s s❡❝t✐♦♥ ✇✐t❤ ❈ ❝♦❞❡ ❢♦r ▲❛❣r❛♥❣❡ ❛♥❞ ❍❡r♠✐t❡ ✐♥t❡r♣♦❧❛t✐♦♥✳ ❚❤❡ ✜rst ♣r♦❝❡❞✉r❡ ✇♦r❦s ♦✉t t❤❡ ▲❛❣r❛♥❣✐❛♥ ✐♥t❡r✲ ♣♦❧❛t✐♥❣ ❝✉❜✐❝ ♣❛r❛♠❡tr✐❝ ♣♦❧②♥♦♠✐❛❧ t❤r♦✉❣❤ ❢♦✉r ♣♦✐♥ts ✐♥ t❤r❡❡ ❞✐♠❡♥s✐♦♥s✳ ❚❤❡ ♣♦✐♥ts ✇✐❧❧ ❜❡ s✉♣♣❧✐❡❞ ✐♥ ♣①✱ ♣②✱ ❛♥❞ ♣③✳ ❚❤❡ 0✱ ❛♥❞ t❤❡ ♣❛r❛♠✲ ♣❛r❛♠❡t❡r ♦♥ t❤❡ ❝✉r✈❡ ❛t t❤❡ ✜rst ♣♦✐♥t ✇✐❧❧ ❜❡ 1❀ t❤❡ ❝♦❡✣❝✐❡♥ts ♦❢ t❤❡ ♣♦❧②♥♦♠✐❛❧ ✇✐❧❧ ❜❡ ♣♦❧②①✱ ♣♦❧②②✱ ❛♥❞ ♣♦❧②③❀ ♣♦❧②①❬✸❪ ✐s t❤❡ ❝♦❡✣❝✐❡♥t ♦❢ ❡t❡r ❛t t❤❡ ❧❛st ♣♦✐♥t r❡t✉r♥❡❞ ✐♥ ■♥t❡r♣♦❧❛t✐♦♥ t3 ✐♥ x ✸✼ ❛♥❞ s♦ ♦♥✳ ❚❤❡ ♣❛r❛♠❡t❡r ✈❛❧✉❡s ❛t t❤❡ ♠✐❞❞❧❡ t✇♦ ♣♦✐♥ts ♦♥ t❤❡ ❝✉r✈❡ ✇✐❧❧ ❜❡ r❡t✉r♥❡❞ ✐♥ t✶ ❛♥❞ t✷✳ ★✐♥❝❧✉❞❡ ❁♠❛t❤✳❤❃ ★✐♥❝❧✉❞❡ ❁st❞✐♦✳❤❃ ✴✯ ❆❜s♦❧✉t❡ ✈❛❧✉❡ ♠❛❝r♦ ✯✴ ★❞❡❢✐♥❡ ❢❛❜s✭❛✮ ✭✭✭❛✮ ❁ ✵✳✵✮ ❄ ✭✲✭❛✮✮ ✿ ✭❛✮✮ ✴✯ ❆❧♠♦st ✵ ✲ ❛❞❥✉st ❢♦r ②♦✉r ❛♣♣❧✐❝❛t✐♦♥ ✯✴ ★❞❡❢✐♥❡ ❆❈❈❨ ✭✶✳✵❡✲✻✮ ✐♥t ❧❛❣r❛♥❣❡✭♣①✱♣②✱♣③✱t✶✱t✷✱♣♦❧②①✱♣♦❧②②✱♣♦❧②③✮ ❢❧♦❛t ♣①❬✹❪✱♣♦❧②①❬✹❪❀ ❢❧♦❛t ♣②❬✹❪✱♣♦❧②②❬✹❪❀ ❢❧♦❛t ♣③❬✹❪✱♣♦❧②③❬✹❪❀ ❢❧♦❛t ✯t✶✱✯t✷❀ ④ ❢❧♦❛t ①❞✱②❞✱③❞✱❞❢❧❀ ✐♥t ✐❀ ✴✯ ✯✴ ❙✉♠ t❤❡ ❞✐st❛♥❝❡s ❜❡t✇❡❡♥ t❤❡ ♣♦✐♥ts t♦ ✉s❡ t♦ s❝❛❧❡ t✶ ❛♥❞ t✷✳ ◆♦t❡ t❤❡ ❡①tr❡♠❡❧② t✐r❡s♦♠❡ ❝❛st✐♥❣ t❤❛t ♥❡❡❞s t♦ ❜❡ ❞♦♥❡ ❜❡❝❛✉s❡ ❛❧❧ ♦❢ t❤❡ st❛♥❞❛r❞ ❈ ♠❛t❤s ❧✐❜r❛r② ✐s ✐♥ ❞♦✉❜❧❡s✳ ❞❢❧ ❂ ✵✳✵❀ ❢♦r✭✐ ❂ ✶❀ ✐ ❁ ✹❀ ✐✰✰✮ ④ ①❞ ❂ ♣①❬✐❪ ✲ ♣①❬✐✲✶❪❀ ②❞ ❂ ♣②❬✐❪ ✲ ♣②❬✐✲✶❪❀ ③❞ ❂ ♣③❬✐❪ ✲ ♣③❬✐✲✶❪❀ ❞❢❧ ❂ ❞❢❧ ✰ ✭❢❧♦❛t✮sqrt✭✭❞♦✉❜❧❡✮ ✭①❞✯①❞ ✰ ②❞✯②❞ ✰ ③❞✯③❞✮✮❀ ❛r❛♠❡tr✐❝ ❝✉r✈❡s ❛♥❞ s✉r❢❛❝❡s ✸✽ ⑥ ✐❢ ✭✐ ❂❂ ✶✮ ✯t✶ ❂ ❞❢❧❀ ✐❢ ✭✐ ❂❂ ✷✮ ✯t✷ ❂ ❞❢❧❀ ✐❢ ✭❞❢❧ ❁ ❆❈❈❨✮ ④ ❢♣r✐♥t❢✭st❞❡rr✱ ✧▲❛❣r❛♥❣❡✿ ❝✉r✈❡ t♦♦ s❤♦rt✿ ✪❢❭♥✧✱❞❢❧✮❀ r❡t✉r♥✭✶✮❀ ⑥ ✯t✶ ❂ ✯t✶✴❞❢❧❀ ✯t✷ ❂ ✯t✷✴❞❢❧❀ ✴✯ ✯✴ ❈❛❧❧ t❤❡ ♣r♦❝❡❞✉r❡ t♦ ❝♦♠♣✉t❡ t❤❡ ❝♦❡❢❢✐❝✐❡♥ts ✐♥ ❡❛❝❤ ❝♦♦r❞✐♥❛t❡✳ ✐❢✭❧❛❣r❛♥❣❡❴❝♦❡❢❢s✭♣①✱♣♦❧②①✱t✶✱t✷✮✮ r❡t✉r♥✭✷✮❀ ✐❢✭❧❛❣r❛♥❣❡❴❝♦❡❢❢s✭♣②✱♣♦❧②②✱t✶✱t✷✮✮ r❡t✉r♥✭✸✮❀ ✐❢✭❧❛❣r❛♥❣❡❴❝♦❡❢❢s✭♣③✱♣♦❧②③✱t✶✱t✷✮✮ r❡t✉r♥✭✹✮❀ r❡t✉r♥✭✵✮❀ ⑥ ✴✯ ❧❛❣r❛♥❣❡ ✯✴ ✴✯ ✯✴ r♦❝❡❞✉r❡ t♦ ❝♦♠♣✉t❡ t❤❡ ❝♦❡❢❢✐❝✐❡♥ts ✐♥ ♦♥❡ ❞✐♠❡♥s✐♦♥ ♦❢ t❤❡ ▲❛❣r❛♥❣✐❛♥ ❝✉❜✐❝ t❤r♦✉❣❤ ❢♦✉r ♣♦✐♥ts✳ ❚❤❡ ❝♦❞❡ r❡❢❧❡❝ts t❤❡ ❛❧❣❡❜r❛✳ ✐♥t ❧❛❣r❛♥❣❡❴❝♦❡❢❢s✭♣✱♣♦❧②✱t✶✱t✷✮ ❢❧♦❛t ♣❬✹❪✱♣♦❧②❬✹❪❀ ❢❧♦❛t ✯t✶✱✯t✷❀ ④ ❢❧♦❛t ❞✶✱❞✷✱❞✸✱t✶s✱t✷s✱t✶❝✱t✷❝✱❞❡♥♦♠✱tt❀ ■♥t❡r♣♦❧❛t✐♦♥ ✸✾ ❞✶ ❂ ♣❬✶❪ ✲ ♣❬✵❪❀ ❞✷ ❂ ♣❬✷❪ ✲ ♣❬✵❪❀ ❞✸ ❂ ♣❬✸❪ ✲ ♣❬✵❪❀ t✶s ❂ ✭✯t✶✮✯✭✯t✶✮❀ t✷s ❂ ✭✯t✷✮✯✭✯t✷✮❀ t✶❝ ❂ t✶s✯✭✯t✶✮❀ t✷❝ ❂ t✷s✯✭✯t✷✮❀ ❞❡♥♦♠ ❂ ✭t✷s ✲ ✭✯t✷✮✮✯t✶❝❀ ✐❢ ✭❢❛❜s✭❞❡♥♦♠✮ ❁ ❆❈❈❨✮ ④ ❢♣r✐♥t❢✭st❞❡rr✱ ✧▲❛❣r❛♥❣❡❴❝♦❡❢❢s✿ ✐♥❝r❡♠❡♥ts t♦♦ s❤♦rt✿ ✪❢❭♥✧✱ ❞❡♥♦♠✮❀ r❡t✉r♥✭✶✮❀ ⑥ tt ❂ ✭✲t✷❝ ✰ ✭✯t✷✮✮✯t✶s ✰ ✭t✷❝ ✲ t✷s✮✯✭✯t✶✮❀ ♣♦❧②❬✸❪ ❂ ✭❞✸✯✭✯t✷✮ ✲ ❞✷✮✯t✶s ✰ ✭✲❞✸✯t✷s ✰ ❞✷✮✯✭✯t✶✮ ✰ ❞✶✯t✷s ✲ ❞✶✯✭✯t✷✮✴❞❡♥♦♠ ✰ tt❀ ♣♦❧②❬✷❪ ❂ ✭✲❞✸✯✭✯t✷✮ ✰ ❞✷✮✯t✶❝ ✰ ✭❞✸✯t✷❝ ✲ ❞✷✮✯✭✯t✶✮ ✰ ❞✶✯t✷❝ ✰ ❞✶✯✭✯t✷✮✴❞❡♥♦♠ ✰ tt❀ ♣♦❧②❬✶❪ ❂ ✭❞✸✯t✷s ✲ ❞✷✮✯t✶❝ ✰ ✭✲❞✸✯t✷❝ ✰ ❞✷✮✯t✶s ✰ ❞✶✯t✷❝ ✲ ❞✶✯t✷s✴❞❡♥♦♠ ✰ tt❀ ♣♦❧②❬✵❪ ❂ ♣❬✵❪❀ r❡t✉r♥✭✵✮❀ ⑥ ✴✯ ❧❛❣r❛♥❣❡❴❝♦❡❢❢s ✯✴ ❚❤❡ s❡❝♦♥❞ ♣r♦❝❡❞✉r❡ ❝♦♠♣✉t❡s t❤❡ ❍❡r♠✐t❡ ✐♥t❡r♣♦❧❛♥t ✐♥ t❤r❡❡ ❛r❛♠❡tr✐❝ ❝✉r✈❡s ❛♥❞ s✉r❢❛❝❡s ✹✵ ❞✐♠❡♥s✐♦♥s t❤r♦✉❣❤ t✇♦ ♣♦✐♥ts ✇✐t❤ t✇♦ ❣r❛❞✐❡♥t ✈❡❝t♦rs ❛t t❤❡ ❡♥❞s✳ ❚❤❡ ♣♦✐♥ts ❛r❡ ♣✵ ❛♥❞ ♣✶✱ ❛♥❞ t❤❡ ❣r❛❞✐❡♥ts ❛r❡ ❣✵ ❛♥❞ ❣✶✳ ❚❤❡ ❝♦❡✣❝✐❡♥ts ♦❢ t❤❡ ✐♥t❡r♣♦❧❛t✐♥❣ ♣♦❧②♥♦♠✐❛❧ ❛r❡ r❡t✉r♥❡❞ ✐♥ ♣♦❧②①✱ ♣♦❧②②✱ ❛♥❞ ♣♦❧②③✳ ❚❤❡ ❛❧❣❡❜r❛ ✐♥ t❤✐s ❝❛s❡ ✐s ♠✉❝❤ s✐♠♣❧❡r t❤❛♥ t❤❛t ❢♦r ▲❛❣r❛♥❣✐❛♥ ✐♥t❡r♣♦❧❛t✐♦♥✳ ✈♦✐❞ ❤❡r♠✐t❡✭♣✵✱♣✶✱❣✵✱❣✶✱♣♦❧②①✱♣♦❧②②✱♣♦❧②③✮ ❢❧♦❛t ♣✵❬✸❪✱♣✶❬✸❪✱❣✵❬✸❪✱❣✶❬✸❪❀ ❢❧♦❛t ♣♦❧②①❬✹❪✱♣♦❧②②❬✹❪✱♣♦❧②③❬✹❪❀ ④ ✈♦✐❞ ❤❡r♠✐t❡❴❝♦❡❢❢s✭✮❀ ❤❡r♠✐t❡❴❝♦❡❢❢s✭♣✵❬✵❪✱♣✶❬✵❪✱❣✵❬✵❪✱❣✶❬✵❪✱♣♦❧②①✮❀ ❤❡r♠✐t❡❴❝♦❡❢❢s✭♣✵❬✶❪✱♣✶❬✶❪✱❣✵❬✶❪✱❣✶❬✶❪✱♣♦❧②②✮❀ ❤❡r♠✐t❡❴❝♦❡❢❢s✭♣✵❬✷❪✱♣✶❬✷❪✱❣✵❬✷❪✱❣✶❬✷❪✱♣♦❧②③✮❀ ⑥ ✴✯ ❤❡r♠✐t❡ ✯✴ ✈♦✐❞ ❤❡r♠✐t❡❴❝♦❡❢❢s✭♣✵✱♣✶✱❣✵✱❣✶✱♣♦❧②✮ ❢❧♦❛t ♣✵✱♣✶✱❣✵✱❣✶❀ ❢❧♦❛t ♣♦❧②❬✹❪❀ ④ ❢❧♦❛t ❞✱❣❀ ❞ ❂ ♣✶ ✲ ♣✵ ✲ ❣✵❀ ❣ ❂ ❣✶ ✲ ❣✵❀ ♣♦❧②❬✵❪ ♣♦❧②❬✶❪ ♣♦❧②❬✷❪ ♣♦❧②❬✸❪ ❂ ❂ ❂ ❂ ♣✵❀ ❣✵❀ ✸✳✵✯❞ ✲ ❣❀ ✲✷✳✵✯❞ ✰ ❣❀ ⑥ ✴✯ ❤❡r♠✐t❡❴❝♦❡❢❢s ✯✴ Surface patches ❙✉r❢❛❝❡ ♣❛t❝❤❡s ✹✶ Q = F(t, u) 0 ≤ t ≤ 1, 0 ≤ u ≤ 1✳ ✸✭✐✐✮✖❆ ♣❛r❛♠❡tr✐❝ ♣❛t❝❤ ✐♥t❡r✈❛❧ ❞❡✜♥❡❞ ♦✈❡r t❤❡ ❙✉r❢❛❝❡ ♣❛t❝❤❡s ❛r❡ ♣❛r❛♠❡tr✐❝ s✉r❢❛❝❡s ♦❢ t❤❡ ❢♦r♠ x = f1 (t, u) y = f2 (t, u) z = f3 (t, u) ✭✇❤✐❝❤ ✇❡ ❝❛♥ ❛❧s♦ ✇r✐t❡ ✇✐t❤ ✈❡❝t♦r ❝♦❡✣❝✐❡♥ts ✱ ❛s Q = F(t, u) ❛ ♣❛♣❡r✲s❛✈✐♥❣ ♠❡❛s✉r❡ t❤❛t ✇✐❧❧ ❜❡ ✐♥❝r❡❛s✐♥❣❧② ✉s❡❞ ✐♥ t❤✐s ❝❤❛♣t❡r✮✳ ❆ ♣❛t❝❤ ❝❛♥ ❜❡ ❞❡✜♥❡❞ ♦✈❡r ❛♥② ♣❛r❛♠❡tr✐❝ ♣♦rt✐♦♥ ♦❢ t❤❡ (t, u) ♣❛r❛♠❡t❡r s♣❛❝❡ ✱ ❜✉t ✐s ❡❛s✐❡st t♦ ❞❡❛❧ ✇✐t❤ ♦✈❡r t❤❡ t✇♦✲❞✐♠❡♥s✐♦♥❛❧ ✐♥t❡r✈❛❧✿ 0≤ t ≤1 0 ≤ u ≤ 1.
Dt ❚❤❡ ❝✉r✈❛t✉r❡ ♦❢ ❛ ♣❛r❛♠❡tr✐❝ ❝✉r✈❡ ✐s ❣✐✈❡♥ ❜② t❤❡ ❢♦❧❧♦✇✐♥❣ ❢♦r✲ ♠✉❧❛✱ ✇❤✐❝❤ ✐♥✈♦❧✈❡s ❛ ✈❡❝t♦r ♣r♦❞✉❝t ❜❡t✇❡❡♥ t❤❡ ✜rst ❛♥❞ s❡❝♦♥❞ ❞❡r✐✈❛t✐✈❡s✿ dQ × d2 Q .
T✱ ❢♦r ❛♥② ✜①❡❞ ✈❛❧✉❡ ♦❢ t ♦r u✱ ✇❡ ❣❡t ♦✉t ❛ ❝✉❜✐❝ ✐s♦✲♣❛r❛♠❡tr✐❝ ❝✉r✈❡ ✐♥ t❤❡ ♦t❤❡r ♣❛r❛♠❡t❡r✳ ❆s ✇❡❧❧ ❛s ❦♥♦✇✐♥❣ t❤❡ ♣♦s✐t✐♦♥ ♦❢ t❤❡ ❜♦✉♥❞❛r② ❝✉r✈❡s✱ ✇❡ ♥❡❡❞ t♦ ♠❛t❝❤ t❛♥❣❡♥ts✖❛♥❞ ♠❛②❜❡ ❤✐❣❤❡r ❞❡r✐✈❛t✐✈❡s✱ r❛❞✐✉s ♦❢ ❝✉r✈❛✲ t✉r❡ ❡t❝✳✖ ❛❝r♦ss t❤❡ ❜♦✉♥❞❛r✐❡s✳ t❛♥❣❡♥t ❛❝r♦ss t❤❡ u=0 ❞✐✛❡r❡♥t✐❛t❡ ✇✐t❤ r❡s♣❡❝t t♦ ∂x = ∂u + + + ❚❤❡♥ s❡t u=0 ▲❡t✬s ✜♥❞ ❛♥ ❡①♣r❡ss✐♦♥ ❢♦r t❤❡ ❡❞❣❡ ♦❢ ❛ ❈❛rt❡s✐❛♥ ♣r♦❞✉❝t ♣❛t❝❤✳ ❋✐rst u✿ 3a0 t3 u2 + 2a1 t3 u + a2 t3 3a4 t2 u2 + 2a5 t2 u + a6 t2 3a8 tu2 + 2a9 tu + a10 t 3a12 u2 + 2a13 u + a14 .
Elements of Noncommutative Geometry by Gracia-Bondia J.M., Varilly J.C., Figueroa H.
by Edward
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