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Teoria da Relatividade Geral Prof. Dr. Marco André Ferreira Dias Camila Cezar de Lima Washington de Araujo Bandeira LISTA I a) Mostre que ∆𝑠 = ∆𝜌 √(𝜆2 + 1) + (𝜌 𝑑𝜙 𝑑𝜌 )² 𝑑𝑠2 = 𝑑𝜌2 + (𝜌𝑑𝜙)2 + (𝑑𝑧)2 (Δ𝑠)2 = (Δ𝜌)2 + 𝜌(Δ𝜙)² + (Δ𝑧)2 (Δ𝑠)2 = Δ𝜌2 + [𝜌 𝑑𝜙 𝑑𝜌 Δ𝜌] ² + (λΔ𝜌)2 (Δ𝑠)2 = Δ𝜌2(1 + 𝜆2) + 𝜌2 ( 𝑑𝜙 𝑑𝜌 ) 2 Δ𝜌² (Δ𝑠)2 = Δ𝜌2 [1 + 𝜆2 + 𝜌2 ( 𝑑𝜙 𝑑𝜌 ) 2 ] Δs = Δρ √1 + 𝜆2 + 𝜌2 ( 𝑑𝜙 𝑑𝜌 ) 2 Δs = Δρ √(𝜆2 + 1) + (𝜌 𝑑𝜙 𝑑𝜌 )² b) Seja 𝑓 = √(𝜆2 + 1) + (𝜌 𝑑𝜙 𝑑𝜌 )² ou ainda 𝑓 = √(𝜆2 + 1) + (𝜌𝜙′)² Assim, 𝑓 = 𝑓 (ρ, 𝜙′) então 𝜕𝑓 𝜕𝜙 = 0 Da equação de Euler-Lagrange, temos 𝜕𝑓 𝜕𝜙 = 𝑑 𝑑𝜌 ( 𝜕𝑓 𝜕𝜌′ ) Portanto, 𝑑 𝑑𝜌 ( 𝜕𝑓 𝜕𝜙′ ) = 0 logo, 𝝏𝒇 𝝏𝝓′ = 𝒄𝒐𝒏𝒔𝒕𝒂𝒏𝒕𝒆 c) Mostre que 𝜙(𝜌) = 𝜙0 + √𝜆2 + 1 𝑐𝑜𝑠 −1 ( 𝑐 𝜌 ) Usando a equação 𝑓 (𝜌, 𝜙′) = √(𝜆2 + 1) + (𝜌𝜙′)² obtemos, 𝜕𝑓 𝜕𝜙′ = 1 2 [(𝜆2 + 1) + (𝜌𝜙′)²]− 1 2(2𝜌²𝜙′) = 𝑐 [(𝜆2 + 1) + (𝜌𝜙′)²]− 1 2(𝜌²𝜙′) = 𝑐 𝜙′ = 𝑐 𝜌2 √(𝜆2 + 1) + (𝜌𝜙′)² 𝜙′2 = 𝑐² 𝜌4 [(𝜆2 + 1) + (𝜌𝜙′)²] 𝜙′2 = 𝑐² 𝜌4 (𝜆2 + 1) + 𝑐² 𝜌4 𝜌²𝜙² 𝜙′2 = 𝑐² 𝜌4 (𝜆2 + 1) + 𝑐² 𝜌2 𝜙² 𝜙′2 − 𝑐² 𝜌2 𝜙² = 𝑐2 𝜌4 (𝜆2 + 1) 𝑑𝜙 𝑑𝜌 = √𝜆2 + 1 𝑐 𝜌2 [ 1 √1 − 𝑐² 𝜌²] Seja 𝑢 = 𝑐 𝜌 então, 𝑑𝑢 = − 𝑐 𝜌² 𝑑𝜌 𝑑𝜙 𝑑𝜌 = √𝜆2 + 1 [ −𝑑𝑢 √1 − 𝑢² ] Lembrando que 𝑑 𝑑𝜌 (𝑎𝑟𝑐 cos 𝑢) = − 1 √1−𝑢² 𝑑𝑢 Então, 𝑑𝜙 𝑑𝜌 = √𝜆2 + 1 𝑑 𝑑𝜌 (𝑎𝑟𝑐 cos 𝑐 𝜌 ) 𝑑𝜙 = √𝜆2 + 1 [ 𝑑 𝑑𝜌 (𝑎𝑟𝑐 cos 𝑐 𝜌 )] 𝑑𝜌 ∫ 𝑑𝜙 𝜙 𝜙0 = √𝜆2 + 1 [(𝑎𝑟𝑐 cos 𝑐 𝜌 )] 𝜙 − 𝜙0 = √𝜆2 + 1𝑎𝑟𝑐 cos ( 𝑐 𝜌 ) 𝜙 = 𝜙0 + √𝜆2 + 1 𝑎𝑟𝑐 cos ( 𝑐 𝜌 ) d) 𝜌 cos (𝜙(𝜌) − 𝜙0) = 𝑐 Partindo de 𝜙 − 𝜙0 = √𝜆2 + 1 𝑎𝑟𝑐 cos ( 𝑐 𝜌 ) para 𝜆 = 0 temos, 𝜙 − 𝜙0 = 𝑎𝑟𝑐 cos ( 𝑐 𝜌 ) cos(𝜙 − 𝜙0) = 𝑐 𝜌 cos(𝜙 − 𝜙0) = 𝑐 𝜌 ρ cos(𝜙 − 𝜙0) = 𝑐 e) Para 𝜙0 = 0 temos: ρ cos(𝜙) = 𝑐 Sendo ρ cos(ϕ) = x Logo, x = c f) y x 𝜌 ⋅ 𝑐𝑜𝑠𝜙 = 𝑐 = 𝑥 𝜌 ⋅ cos(𝜙 − 𝜙0) = 𝑐, 𝜙0 = 0 𝜌 ⋅ cos 𝜙 = 𝑐 ⇒ 𝜙(𝜌) = 𝑎𝑟𝑐 𝑐𝑜𝑠 ( 𝑐 𝜌 ) reta perpendicular a linha com inclinação – a uma distância “c” da origem . 𝜌 ⋅ cos𝜙 = 𝑐 g) 𝑧 = 𝜆𝜌 𝑑𝑧 = 𝜆𝑑𝜌 𝑑𝑙2 = 𝜆𝑑𝜌 + 𝑑𝜌2 reajustando, temos: 𝑑𝑙2 = (𝜆2 + 1)𝑑𝜌 𝜂 = 𝜌𝜙 𝑑𝜂 𝑑𝑙 = 𝜕𝜂 𝜕𝜌 𝑑𝜌 𝑑𝑙 + 𝜕𝜂 𝜕𝜙 𝑑𝜙 𝑑𝑙 ( 𝑑𝜌 𝑑𝑙 ) 2 = 1 𝜆2 + 1 𝑑𝜌 𝑑𝑙 = 1 √𝜆2 + 1 𝑑𝜙 𝑑𝑙 = 0 𝜕𝜂 𝜕𝜌 = 𝜙 e 𝜕𝜂 𝜕𝜙 = 𝜌 𝑑𝜂 𝑑𝑙 = 𝜙 𝜆2 + 1 𝑑²𝜂 𝑑𝑙² = 1 𝜆2 + 1 𝑑𝜙 𝑑𝑙 𝑑²𝜂 𝑑𝑙² = 0 Se, 𝑑²𝜂 𝑑𝑙² = −𝑘𝜂 Logo, −𝑘𝜂 = 0 e 𝑘 = 0 LISTA II 1) 𝜕�̂� 𝜕𝑟 = 𝜕 𝜕𝑟 (𝑥 ̂𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 + �̂�𝑠𝑒𝑛𝜃𝑠𝑒𝑛𝜙 + �̂�𝑐𝑜𝑠𝜃) = 0 (1) 𝜕�̂� 𝜕𝜃 = 𝜕 𝜕𝜃 (𝑥 ̂𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 + �̂�𝑠𝑒𝑛𝜃𝑠𝑒𝑛𝜙 + �̂�𝑐𝑜𝑠𝜃) 𝜕�̂� 𝜕𝜃 = 𝑥 ̂𝑐𝑜𝑠𝜃𝑐𝑜𝑠𝜙 + �̂�𝑐𝑜𝑠𝜃𝑠𝑒𝑛𝜙 − �̂�𝑠𝑒𝑛𝜃 𝜕�̂� 𝜕𝜃 = 𝑐𝑜𝑠𝜃(𝑥 ̂𝑐𝑜𝑠𝜙 + �̂�𝑠𝑒𝑛𝜙) − �̂�𝑠𝑒𝑛𝜃 (2) 𝜕�̂� 𝜕𝜙 = 𝜕 𝜕𝜙 (𝑥 ̂𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 + �̂�𝑠𝑒𝑛𝜃𝑠𝑒𝑛𝜙 + �̂�𝑐𝑜𝑠𝜃) 𝜕�̂� 𝜕𝜙 = − 𝑥 ̂𝑠𝑒𝑛𝜃𝑠𝑒𝑛𝜙 + �̂�𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 𝜕�̂� 𝜕𝜙 = 𝑠𝑒𝑛 𝜃 (− 𝑥 ̂𝑒𝑛𝜙 + �̂�𝑐𝑜𝑠𝜙) (3) �̂� = �̂� × �̂� 𝑠𝑒𝑛𝜃 = 1 𝑠𝑒𝑛𝜃 ⌈ �̂� �̂� �̂� 0 0 1 𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 𝑐𝑜𝑠𝜃 ⌉ �̂� = �̂�𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 − 𝑥 ̂𝑠𝑒𝑛𝜃𝑠𝑒𝑛𝜙 = −𝑥 ̂𝑠𝑒𝑛𝜙 + �̂�𝑐𝑜𝑠𝜙 (4) 𝜃 = �̂� × �̂� = ⌈ �̂� �̂� �̂� −𝑠𝑒𝑛𝜃 𝑐𝑜𝑠𝜙 0 𝑠𝑒𝑛𝜃𝑐𝑜𝑠𝜙 𝑠𝑒𝑛𝜃𝑠𝑒𝑛𝜙 𝑐𝑜𝑠𝜃 ⌉ 𝜃 = 𝑥 ̂𝑐𝑜𝑠𝜃𝑐𝑜𝑠𝜙 − 𝑧 ̂𝑠𝑒𝑛𝜃𝑠𝑒𝑛2𝜙 − 𝑧 ̂𝑠𝑒𝑛𝜃𝑐𝑜𝑠2𝜙 + �̂�𝑠𝑒𝑛𝜙𝑐𝑜𝑠𝜃 𝜃 = 𝑐𝑜𝑠𝜃 (𝑥 ̂𝑐𝑜𝑠𝜙 + �̂�𝑠𝑒𝑛𝜙) − 𝑠𝑒𝑛𝜃𝑧 ̂ (5) Portanto, De (1), 𝜕�̂� 𝜕𝑟 = 0 De (2) e (5), 𝜕�̂� 𝜕𝜃 = 𝜃 De (3) e (4), 𝜕�̂� 𝜕𝜙 = 𝜃 𝑠𝑒𝑛𝜃 E, se �⃗� = 𝑟�̂� e �̂� = 𝑟 𝑟 Portanto, �̂� = 𝑟�̂� Logo, �⃗� = 𝑟 Portanto, 𝑑�⃗� = 𝑑𝑟 Dado que 𝑑𝑟 = 𝑑(𝑟𝑑�̂�) 𝑑𝑟 = 𝑟𝑑�̂� + �̂�𝑑𝑟 𝑑𝑟 = 𝑟 ( 𝜕�̂� 𝜕𝑟 𝑑𝑟 + 𝜕�̂� 𝜕𝜃 𝑑𝜃 + 𝜕�̂� 𝜕𝜙 𝑑𝜙) + �̂�𝑑𝑟 𝑑𝑟 = 𝑟(0𝑑𝑟 + 𝜃𝑑𝜃 + �̂�𝑠𝑒𝑛𝜃𝑑𝜙) + �̂�𝑑𝑟 𝑑𝑟 = 𝑟(𝜃𝑑𝜃 + �̂�𝑠𝑒𝑛𝜃𝑑𝜙) + �̂�𝑑𝑟 𝑑𝑟 = 𝑟(𝜃𝑑𝜃 + �̂�𝑠𝑒𝑛𝜃𝑑𝜙) + �̂�𝑑𝑟 𝑑𝑟 = �̂�𝑑𝑟 + 𝑟𝜃𝑑𝜃 + �̂�𝑟𝑠𝑒𝑛𝜃𝑑𝜙 Como 𝑑�⃗� = 𝑑𝑟 temos: 𝑑�⃗� = �̂�𝑑𝑟 + 𝜃𝑟𝑑𝜃 + �̂�𝑟𝑠𝑒𝑛𝜃𝑑𝜙 2) 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴 𝑑�⃗�𝑑�⃗� − 𝐵(𝑥.⃗⃗⃗ ⃗ 𝑑�⃗�)2 − 𝐶𝑑𝑡(�⃗�. 𝑑�⃗�) 𝑑�⃗� = �̂�𝑑𝑟 + 𝜃𝑟𝑑𝜃 + �̂�𝑟𝑠𝑒𝑛𝜃𝑑𝜙 �⃗� = 𝑟�̂� 𝑑�⃗�𝑑�⃗� = 𝑑𝑟2 + 𝑟2𝑑𝜃2 + 𝑟2𝑠𝑒𝑛2𝜃𝑑𝜙² �⃗�. 𝑑�⃗� = 𝑟𝑑𝑟 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴 ( 𝑑𝑟2 + 𝑟2𝑑𝜃2 + 𝑟2𝑠𝑒𝑛2𝜃𝑑𝜙2) − 𝐵(𝑟𝑑𝑟)2 − 𝐶𝑑𝑡(𝑟𝑑𝑟) 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐴𝑑𝑟2 − 𝐵𝑟²𝑑𝑟² − 𝐶𝑟𝑑𝑡𝑑𝑟 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − (𝐴 + 𝐵𝑟2)𝑑𝑟2 − 𝐶𝑟𝑑𝑡𝑑𝑟 Considerando, 𝐴 + 𝐵𝑟2 = 𝐸 e 𝐶𝑟 = 𝐹 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐸𝑑𝑟2 − 𝐹𝑑𝑡𝑑𝑟 Renomeamos os termos E B e F C: 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 𝐶𝑑𝑟𝑑𝑡 3) Seja t t’ = t + f(r) ou ainda, t’ – t = f(r) Temos que; 𝑑𝑡′ = 𝑑𝑡 + 𝜕𝑓(𝑟) 𝜕𝑟 𝑑𝑟 𝑓(𝑟) = 1 2 ∫ 𝐶 𝐷 𝑑𝑟 𝑑𝑡′ = 𝑑𝑡 + 1 2 𝐶 𝐷 𝑑𝑟 𝑑𝑓(𝑟) 𝑑𝑟 = 1 2 𝐶 𝐷 𝑑𝑠2 = 𝐷(𝑑𝑡′)2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 𝐶𝑑𝑟(𝑑𝑡′) 𝑑𝑠2 = 𝐷 (𝑑𝑡 + 1 2 𝐶 𝐷 𝑑𝑟) 2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 𝐶𝑑𝑟 (𝑑𝑡 + 1 2 𝐶 𝐷 𝑑𝑟) 𝑑𝑠2 = 𝐷 [𝑑𝑡2 + 𝐶 𝐷 𝑑𝑟𝑑𝑡 + 1 4 𝐶 𝐷 𝑑𝑟²] − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 𝐶𝑑𝑟𝑑𝑡 − 𝐶𝑑𝑟 1 2 𝐶 𝐷 𝑑𝑟 𝑑𝑠2 = 𝐷𝑑𝑡2 + 𝐶𝑑𝑟𝑑𝑡 + 1 4 𝐶𝑑𝑟² − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 𝐶𝑑𝑟𝑑𝑡 − 1 2 𝐶² 𝐷 𝑑𝑟² 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 1 2 𝐶² 𝐷 𝑑𝑟² + 1 4 𝐶𝑑𝑟² 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 1 4 𝐶² 𝐷 𝑑𝑟² 4) Da questão 2: 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐴[𝑟2(𝑑𝜃2 + 𝑠𝑒𝑛2𝜃𝑑𝜙2)] − 𝐵𝑑𝑟2 − 𝐶𝑑𝑟𝑑𝑡 Sendo d = d = 0 : 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐵𝑑𝑟2 − 𝐶𝑑𝑟𝑑𝑡 Se a métrica é isotrópica, C = 0: 𝑑𝑠2 = 𝐷𝑑𝑡2 − 𝐵𝑑𝑟2 Sendo 𝑑𝑠2 = 𝑔𝜇𝜈 ⋅ 𝑑𝑥 𝜇 ⋅ 𝑑𝑥𝜈 , para 𝑔𝜇𝜈 = 𝑔𝜇𝜈(�⃗�, 𝑡) Então, 𝐷 = 𝑐2 ⋅ 𝑔𝑡𝑡 e 𝐵 = 𝑐 2 ⋅ 𝑔𝑟𝑟 Assim: 𝑑𝑠2 = 𝑐2 ⋅ 𝑔𝑡𝑡 ⋅ 𝑑𝑡 2 − 𝑐2 ⋅ 𝑔𝑟𝑟 ⋅ 𝑑𝑟 2 Mas, como a luz caminha por geodésicas nulas... 𝑑𝑠2 = 0 ⟹ 𝑐2 ⋅ 𝑔𝑡𝑡 ⋅ 𝑑𝑡 2 = 𝑐2 ⋅ 𝑔𝑟𝑟 ⋅ 𝑑𝑟 2 ( 𝑑𝑦 𝑑𝑥 ) 2 = 𝑐2 ⋅ 𝑔𝑡𝑡 𝑔𝑟𝑟𝑑𝑟 𝑑𝑡 = 𝑐 ⋅ √ 𝑔𝑡𝑡 𝑔𝑟𝑟 Renomeando gtt para g00 : 𝑑𝑟 𝑑𝑡 = 𝑐 ⋅ √ 𝑔00 𝑔𝑟𝑟 LISTA 3 1) 𝐴𝑖;𝑗 − 𝐴𝑗;𝑖 = 𝐴𝑖,𝑗 − 𝐴𝑗,𝑖 𝑇𝑖𝑗;𝑘 + 𝑇𝑗𝑘;𝑖 + 𝑇𝑘𝑖;𝑗 = 𝑇𝑖𝑗,𝑘 + 𝑇𝑗𝑘,𝑖 + 𝑇𝑘𝑖,𝑗 Dado que: 𝐴𝑖;𝑗 = 𝐴𝑖,𝑗 − 𝛤𝑗𝑖 𝑎 ⋅ 𝐴𝑎 e 𝐴𝑗;𝑖 = 𝐴𝑗,𝑖 − 𝛤𝑖𝑗 𝑎 ⋅ 𝐴𝑎 Temos: 𝐴𝑖;𝑗 − 𝐴𝑗;𝑖 = (𝐴𝑖,𝑗 − 𝛤𝑗𝑖 𝑎 ⋅ 𝐴𝑎) − 𝐴𝑗,𝑖 − (𝛤𝑖𝑗 𝑎 ⋅ 𝐴𝑎) 𝐴𝑖;𝑗 − 𝐴𝑗;𝑖 = 𝐴𝑖,𝑗 − 𝛤𝑗𝑖 𝑎 ⋅ 𝐴𝑎 − 𝐴𝑗,𝑖 + 𝛤𝑖𝑗 𝑎 ⋅ 𝐴𝑎 Uma vez que 𝛤𝑗𝑖 𝑎 = 𝛤𝑖𝑗 𝑎 , temos: 𝐴𝑖;𝑗 − 𝐴𝑗;𝑖 = 𝐴𝑖,𝑗 − 𝐴𝑗,𝑖 Para o tensor antissimétrico, definimos: 𝑇𝑖𝑗;𝑘 = 𝑇𝑖𝑗,𝑘 + 𝑇𝑎𝑗 ⋅ 𝛤𝑖𝑘 𝑎 − 𝑇𝑖𝑎 ⋅ 𝛤𝑗𝑘 𝑎 𝑇𝑗𝑘;𝑖 = 𝑇𝑗𝑘,𝑖 + 𝑇𝑏𝑘 ⋅ 𝛤𝑗𝑖 𝑏 − 𝑇𝑗𝑏 ⋅ 𝛤𝑘𝑖 𝑏 𝑇𝑘𝑖;𝑗 = 𝑇𝑘𝑖,𝑗 + 𝑇𝑐𝑖 ⋅ 𝛤𝑘𝑗 𝑐 − 𝑇𝑘𝑐 ⋅ 𝛤𝑖𝑗 𝑐 Então: 𝑇𝑖𝑗;𝑘 + 𝑇𝑗𝑘;𝑖 + 𝑇𝑘𝑖;𝑗 = (𝑇𝑖𝑗,𝑘 + 𝑇𝑎𝑗 ⋅ 𝛤𝑖𝑘 𝑎 − 𝑇𝑖𝑎 ⋅ 𝛤𝑗𝑘 𝑎) + (𝑇𝑗𝑘,𝑖 + 𝑇𝑏𝑘 ⋅ 𝛤𝑗𝑖 𝑏 − 𝑇𝑗𝑏 ⋅ 𝛤𝑘𝑖 𝑏) + (𝑇𝑘𝑖,𝑗 + 𝑇𝑐𝑖 ⋅ 𝛤𝑘𝑗 𝑐 − 𝑇𝑘𝑐 ⋅ 𝛤𝑖𝑗 𝑐) Devido à antissimetria do tensor Tij e à simetria dos símbolos de Christoffel: 𝑇𝑖𝑗;𝑘 + 𝑇𝑗𝑘;𝑖 + 𝑇𝑘𝑖;𝑗 = 𝑇𝑖𝑗,𝑘 + 𝑇𝑎𝑗 ⋅ 𝛤𝑖𝑘 𝑎 − 𝑇𝑖𝑎 ⋅ 𝛤𝑗𝑘 𝑎 + 𝑇𝑗𝑘,𝑖 + 𝑇𝑏𝑘 ⋅ 𝛤𝑗𝑖 𝑏 − 𝑇𝑗𝑏 ⋅ 𝛤𝑘𝑖 𝑏 + 𝑇𝑘𝑖,𝑗 + 𝑇𝑐𝑖 ⋅ 𝛤𝑘𝑗 𝑐 − 𝑇𝑘𝑐 ⋅ 𝛤𝑖𝑗 𝑐 Portanto: 𝑇𝑖𝑗;𝑘 + 𝑇𝑗𝑘;𝑖 + 𝑇𝑘𝑖;𝑗 = 𝑇𝑖𝑗,𝑘 + 𝑇𝑗𝑘,𝑖 + 𝑇𝑘𝑖,𝑗 2) 𝑑𝑠2 = 𝑑𝑠2 + 𝑟2 ⋅ 𝑑𝜙2 + 𝑑𝑧2 , são: 𝛤𝜙𝜙 𝑟 = −𝑟, 𝛤𝑟𝜙 𝜙 = 1 𝑟 , 𝛤𝜙𝑟 𝜙 = 1 𝑟 Temos: 𝑔𝑎𝑏 = ( 1 0 0 0 𝑟2 0 0 0 1 ) e 𝑔𝑎𝑏 = ( 1 0 0 0 1 𝑟2 0 0 0 1 ) Tomando a definição dos símbolos de Christoffel de segunda espécie, para os não nulos temos: 𝛤𝑏𝑐 𝑎 = 1 2 ⋅ 𝑔𝑎𝑑 ⋅ ( 𝜕𝑔𝑏𝑑 𝜕𝑥𝑐 + 𝜕𝑔𝑐𝑑 𝜕𝑥𝑐 − 𝜕𝑔𝑏𝑐 𝜕𝑥𝑐 ) Para a = r, b = , c = e d = r: 𝛤𝜙𝜙 𝑟 = 1 2 ⋅ 𝑔𝑟𝑟 ⋅ ( 𝜕𝑔𝜙𝑟 𝜕𝑥𝜙 + 𝜕𝑔𝜙𝑟 𝜕𝑥𝜙 − 𝜕𝑔𝜙𝜙 𝜕𝑥𝑟 ) = 1 2 ⋅ (1) ⋅ (−2 ⋅ 𝑟) = −𝑟 Para a = , b = r, c = e d = : 𝛤𝑟𝜙 𝜙 = 1 2 ⋅ 𝑔𝜙𝜙 ⋅ ( 𝜕𝑔𝑟𝜙 𝜕𝑥𝜙 + 𝜕𝑔𝜙𝜙 𝜕𝑥𝑟 − 𝜕𝑔𝑟𝜙 𝜕𝑥𝜙 ) = 1 2 ⋅ ( 1 𝑟2 ) ⋅ (2 ⋅ 𝑟) = 1 𝑟 Para a = , b = , c = r e d = : 𝛤𝜙𝑟 𝜙 = 1 2 ⋅ 𝑔𝜙𝜙 ⋅ ( 𝜕𝑔𝜙𝜙 𝜕𝑥𝑟 + 𝜕𝑔𝑟𝜙 𝜕𝑥𝜙 − 𝜕𝑔𝜙𝑟 𝜕𝑥𝜙 ) = 1 2 ⋅ ( 1 𝑟2 ) ⋅ (2 ⋅ 𝑟) = 1 𝑟 Portanto: 𝛤𝜙𝜙 𝑟 = −𝑟 𝛤𝑟𝜙 𝜙 = 1 𝑟 𝛤𝜙𝑟 𝜙 = 1 𝑟 3) Seja a equação da geodésica: 𝑑2𝑋𝑎 𝑑𝑠2 + Γ𝑏𝑐 𝑎 ⋅ 𝑑𝑋𝑏 𝑑𝑠 ⋅ 𝑑𝑋𝑐 𝑑𝑠 = 0 Tomando os símbolos de Christofell não nulos e a métrica do exercício anterior: Para a = r: 𝑑2𝑟 𝑑𝑠2 + Γ𝜙𝜙 𝑟 ⋅ 𝑑𝜙 𝑑𝑠 ⋅ 𝑑𝜙 𝑑𝑠 = 0 Então: 𝑑2𝑟 𝑑𝑠2 − 𝑟 ⋅ ( 𝑑𝜙 𝑑𝑠 )2 = 0 Para a = : 𝑑2𝜙 𝑑𝑠2 + Γ𝑟𝜙 𝜙 ⋅ 𝑑𝑟 𝑑𝑠 ⋅ 𝑑𝜙 𝑑𝑠 + Γ𝜙𝑟 𝜙 ⋅ 𝑑𝜙 𝑑𝑠 ⋅ 𝑑𝑟 𝑑𝑠 = 0 𝑑2𝜙 𝑑𝑠2 + 1 𝑟 ⋅ 𝑑𝑟 𝑑𝑠 ⋅ 𝑑𝜙 𝑑𝑠 + 1 𝑟 ⋅ 𝑑𝜙 𝑑𝑠 ⋅ 𝑑𝑟 𝑑𝑠 = 0 Então: 𝑑2𝜙 𝑑𝑠2 + 2 𝑟 ⋅ 𝑑𝑟 𝑑𝑠 ⋅ 𝑑𝜙 𝑑𝑠 = 0 Para a = z: 𝑑2𝑧 𝑑𝑠2 + Γ𝑏𝑐 𝑧 ⋅ 𝑑2𝑋𝑏 𝑑𝑠 ⋅ 𝑑2𝑋𝑐 𝑑𝑠 = 0 Termo nulo! Logo: 𝑑2𝑧 𝑑𝑠2 = 0 4) 𝑉;𝛼𝛽 𝜇 = (𝑉,𝛽 𝜇 + Γ𝛽𝜆 𝜇 ⋅ 𝑉𝜆) ;𝛼 𝑉;𝛼𝛽 𝜇 = 𝑉,𝛽𝛼 𝜇 + 𝑉,𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜆 + 𝑉,𝜆 𝜇 ⋅ Γ𝛽𝛼 𝜆 + 𝑉,𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜆 + 𝑉𝜆 ⋅ Γ𝜇𝛽,𝛼 𝜆 − 𝑉𝜆 ⋅ Γ𝜈𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜈 − 𝑉𝜆 ⋅ Γ𝜇𝜈 𝜆 ⋅ Γ𝛽𝛼 𝜈 𝑉;𝛽𝛼 𝜇 = (𝑉,𝛼 𝜇 + Γ𝛼𝜆 𝜇 ⋅ 𝑉𝜆) ;𝛽 𝑉;𝛽𝛼 𝜇 = 𝑉,𝛼𝛽 𝜇 + 𝑉,𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜆 + 𝑉,𝜆 𝜇 ⋅ Γ𝛼𝛽 𝜆 + 𝑉,𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜆 + 𝑉𝜆 ⋅ Γ𝜇𝛼,𝛽 𝜆 − 𝑉𝜆 ⋅ Γ𝜈𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜈 − 𝑉𝜆 ⋅ Γ𝜇𝜈 𝜆 ⋅ Γ𝛼𝛽 𝜈 𝑉;𝛼𝛽 𝜇 − 𝑉;𝛽𝛼 𝜇 = 𝑉,𝛽𝛼 𝜇 + 𝑉,𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜆 + 𝑉,𝜆 𝜇 ⋅ Γ𝛽𝛼 𝜆 + 𝑉,𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜆 + 𝑉𝜆 ⋅ Γ𝜇𝛽,𝛼 𝜆 − 𝑉𝜆 ⋅ Γ𝜈𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜈 − 𝑉𝜆 ⋅ Γ𝜇𝜈 𝜆 ⋅ Γ𝛽𝛼 𝜈 − 𝑉,𝛼𝛽 𝜇 − 𝑉,𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜆 − 𝑉,𝜆 𝜇 ⋅ Γ𝛼𝛽 𝜆 − 𝑉,𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜆 − 𝑉𝜆 ⋅ Γ𝜇𝛼,𝛽 𝜆 + 𝑉𝜆 ⋅ Γ𝜈𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜈 + 𝑉𝜆 ⋅ Γ𝜇𝜈 𝜆 ⋅ Γ𝛼𝛽 𝜈 𝑉;𝛼𝛽 𝜇 − 𝑉;𝛽𝛼 𝜇 = 𝑉𝜆 ⋅ Γ𝜇𝛽,𝛼 𝜆 − 𝑉𝜆 ⋅ Γ𝜈𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜈 − 𝑉𝜆 ⋅ Γ𝜇𝛼,𝛽 𝜆 + 𝑉𝜆 ⋅ Γ𝜈𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜈 𝑉;𝛼𝛽 𝜇 − 𝑉;𝛽𝛼 𝜇 = (Γ𝜇𝛽,𝛼 𝜆 − Γ𝜈𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜈 − Γ𝜇𝛼,𝛽 𝜆 + Γ𝜈𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜈 ) ⋅ 𝑉𝜆 𝑉;𝛼𝛽 𝜇 − 𝑉;𝛽𝛼 𝜇 = (Γ𝜇𝛽,𝛼 𝜆 − Γ𝜇𝛼,𝛽 𝜆 + Γ𝜈𝛼 𝜆 ⋅ Γ𝜇𝛽 𝜈 − Γ𝜈𝛽 𝜆 ⋅ Γ𝜇𝛼 𝜈 ) ⋅ 𝑉𝜆 𝑉;𝛼𝛽 𝜇 − 𝑉;𝛽𝛼 𝜇 = −R𝜇𝛽𝛼 𝜆 ⋅ 𝑉𝜆 𝑉;𝛼𝛽 𝜇 − 𝑉;𝛽𝛼 𝜇 = 𝑅𝜇𝛼𝛽 𝜆 ⋅ 𝑉𝜆
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