Reputation
513
Top tag
Next privilege 1,000 Rep.
Create new tags
Badges
2 12
Newest
 Custodian
Impact
~16k people reached

  • 0 posts edited
  • 0 helpful flags
  • 119 votes cast
Apr
17
suggested rejected edit on Derive an exact formula (solve the recurrence definition) for the following recursive sequence:
Apr
16
comment Inverse laplace transform of $1/(s^2 +1)^{1/2}$
I don't think there is an analytical solution, the inverse laplace transform of this is the bessel function of the first kind.
Apr
16
comment Question about parallel displacement on a surface
Sorry, but I think you misunderstood, I am asking whether the calculation in my question (which is quoted from a problem in the book I mentioned) is right or not, and presumably it is not right because the author explicitly said ‘what's wrong with the following argument’.
Apr
16
reviewed Reviewed Error bound for Composite Simpson's Rule for $f\notin C^4$
Apr
16
comment Question about parallel displacement on a surface
Now I understand it is $v$ dependent, but is the above calculation quoted from the book right? The problem asks to find the fault of the calculation.
Apr
16
comment Which of the following is true for $\int_{1}^{0} x\ln x\, \text dx$?
@robjohn yep, I forgot the $\frac{1}{4}$ factor.
Apr
15
awarded  Custodian
Apr
15
reviewed No Action Needed Setting two equations equal to each other
Apr
14
comment Question about parallel displacement on a surface
@user86418 It should be equal to $\iint K\,ds$, where $K$ is the gaussian curvature.
Apr
14
comment Which of the following is true for $\int_{1}^{0} x\ln x\, \text dx$?
After change of variable, it is $\int_0^{-\infty}xe^x\,dx$.
Apr
14
asked Question about parallel displacement on a surface
Apr
12
comment Are there simple examples of Riemannian manifolds with zero curvature and nonzero torsion
"A visual introduction to Riemannian curvatures and some discrete generalizations" -Saw it on the comment of your other answer, thx!
Apr
12
comment Are there simple examples of Riemannian manifolds with zero curvature and nonzero torsion
Great answer and illustration! May I ask where do these figures come from? I have seen some of these pictures in Nakahara's Geometry, Topology and Physics, what about the others? I would like to read the book contains the torsion figures.
Apr
11
comment RC-Circuit for a LIF-Neuron
Google 'first order linear differential equations'.
Apr
11
comment RC-Circuit for a LIF-Neuron
The solution is for constant current input $I_0$.
Apr
10
accepted A question about the index of vector field
Apr
8
answered A question about the index of vector field
Apr
7
comment A question about the index of vector field
@RyanBudney I think I know how to do it now, since $\mathbf{v}$ can be extended to a nonvanishing vector field on $U$, $\mathbf{v}$ on $M$ can be shrunk continuously into small sphere around any point in $U$, where vector field $\mathbf{v}$ behaves like a constant vector field and has index 0, so the original vector field on $M$ should have index 0. Is this correct? Is this homology?
Apr
7
comment A question about the index of vector field
@RyanBudney exactly.
Apr
7
comment A question about the index of vector field
@RyanBudney Should I say the Brouwer degree of $\mathbf{v}$? It is the degree of map that maps $M$ onto a sphere of the same dimension defined by $\mathbf{v}$.