Recent content by VladZH
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I Geodesics under coordinate transformation
So basically if solution did exist that would mean the metric is flat?- VladZH
- Post #23
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
Thanks for reply I understand the idea that connection can be zero at one point but not in others. But how I can derive it from the equation I wrote? Since that transformation will turn metric components to diagonal in any point. I just want to find an error in my steps- VladZH
- Post #18
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
That is what I meant. Given coordinates xi and metric components gij I find such cordinates x'i=f(x1,...,xn) so that having Jacobian J_j^i=\frac{\partial x_i}{\partial x'_j} I am getting new metric components J^T*g*J=g'= \begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix} Than I solve geodesic...- VladZH
- Post #15
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
So how coordinate transforamtion is different from the example in my first post? For coordinate transform of metric tensor we have J^T*g'*J=g where J is Jacobian matrix.- VladZH
- Post #13
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
What is the difference? What are vector components then?- VladZH
- Post #9
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
I cannot fully understand what you mean. If we want to know vector components x^i in another coordinate system we can use equation x'^j=B^j_i x^i And for components of metric tensor respectively g'_{ij}=A^l_iA^k_j g_{kl} where A = J and B = J^{-1}. Why it is not coordinate transformation if we...- VladZH
- Post #7
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
So in this specific example can I say that g' is equivalent to euclidean metric? For coordinate transformation I can use A-1, right?- VladZH
- Post #5
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
Thanks for reply! Yes, I mean "equation of the form y = ax + b" . The solution of geodesic equation in coordinate system with component of metric as identity matrix gives y = ax + b. So I can take any metric in the coordinate system where its components are identity matrix and solving...- VladZH
- Post #3
- Forum: Differential Geometry
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I Geodesics under coordinate transformation
I will start with an example. Consider components of metric tensor g' in a coordinate system $$ g'= \begin{pmatrix} xy & 1 \\ 1 & xy \\ \end{pmatrix} $$ We can find a transformation rule which brings g' to euclidean metric g=\begin{pmatrix} 1 & 0 \\ 0 & 1\\ \end{pmatrix}, namely...- VladZH
- Thread
- Coordinate Coordinate transformation Geodesics Transformation
- Replies: 23
- Forum: Differential Geometry
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I Find Trajectory from A to B: Approaches & Solutions
This is problem for my video game I tried to solve a simpler problem when we don't have the body C. Let P(r, φ) is a point on the circle. Let s between A and P. Hence, the time for spacecraft from A to B equals Δt=s/v The time for body B to get P is Δt=Δφ/ω. We get d/v=Δφ/ω where φ=sω/v Now...- VladZH
- Post #4
- Forum: Astronomy and Astrophysics
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I Find Trajectory from A to B: Approaches & Solutions
Hello Given: Point A Body B with angular velocity ω C body with radius r Spacecraft with constant velocity v. We neglect the gravity of the bodies B, C The problem: Find the shortest trajectory for spacecraft from A to B What approaches might be here? How might the solution be changed if...- VladZH
- Thread
- Trajectory
- Replies: 3
- Forum: Astronomy and Astrophysics
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B Proof of the identity A\(A\B)=B
Thank you, guys. Seems like I confused with the formultaion- VladZH
- Post #5
- Forum: Set Theory, Logic, Probability, Statistics
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B Proof of the identity A\(A\B)=B
I'm trying to proof an identity from Munkres' Topology A \ ( A \ B ) = B By definition A \ B = {x : x in A and x not in B} A \( A \ B) = A \ (A ∩ Bc) = A ∩ (A ∩ Bc)c = A ∩ (Ac ∪ B) = (A ∩ Ac) ∪ (A ∩ B) = ∅ ∪ (A ∩ B) = A ∩ B What did I miss?- VladZH
- Thread
- Expression Identity Proof
- Replies: 5
- Forum: Set Theory, Logic, Probability, Statistics
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I Proving Effects of Stress-Energy Tensor on Curvature
Ok, I see my approach is wrong. What are the approches to show that change of mass affects the curvature and change of velocity does not? How can we use Einstein field equation here?- VladZH
- Post #6
- Forum: Special and General Relativity
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I Proving Effects of Stress-Energy Tensor on Curvature
Sorry. I'm not talking about covariance- VladZH
- Post #4
- Forum: Special and General Relativity