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jose's user avatar
jose's user avatar
jose's user avatar
jose
  • Member for 10 years, 6 months
  • Last seen this week
  • Champaign, IL, United States
3 votes

xAct xCoba: Geodesic Equation in Components

3 votes
Accepted

Having problem with ChangeOfCurvature function in xAct

3 votes
Accepted

Manipulations with tensors that keep so(3,1) symmetry manifest

3 votes
Accepted

Area of countries given by GeoBoundaries does not equal area in database

3 votes
Accepted

How to change the dimension of a tensor inside a loop using XAct/XTensor?

3 votes
Accepted

Expanding the Riemann tensor (perturbation)

3 votes
Accepted

Using Combinatorica`ListNecklaces in v9

3 votes

AscendingNodeLongitude for the Moon at a given date

3 votes

Counting multiple $-sign string indices in output and replacing them by normal indices

3 votes
Accepted

Commutation of the partial derivatives on scalar in xAct

3 votes
Accepted

Why are Christoffels vanishing depending on choice of basis (xAct)?

3 votes

A problem about the integration of blackbody radiation law using FormulaData. QuantityVariable limits

3 votes
Accepted

Dealing with covariant derivatives (xCoba)

3 votes
Accepted

xAct xCoba: How to extract components of CTensors correctly

3 votes
Accepted

Evaluating covariant derivative terms of a scalar function (xAct, xTras)

3 votes

Sorting Associations by DayName (day of week) using KeySort and/or KeySortBy

2 votes

Format data consistently with Around

2 votes

Location of the point on Earth with the Sun at the zenith

2 votes

in xAct, how to set the components of a tensor to be zero

2 votes
Accepted

xAct define normalization

2 votes

Distance to the ocean

2 votes

Define Conformal Metric in xAct

2 votes
Accepted

Handling different kind of indices in single tensor equation

2 votes
Accepted

How to take derivative of a tensor leading to kronecker delta?

2 votes
Accepted

How to determine computationally the set of linear independent permutations of a tensor with known symmetries?

2 votes

Creating 15x15 matrix out of two 6x6 matrices (by antisymmetrization)

2 votes
Accepted

Unable to simplify tensor expressions with xAct

2 votes

Geographic coordinate transformation to British National Grid

2 votes

GeoGridLines behind Continents in GeoGraphics Plot?

2 votes
Accepted

Explicitly construct tensor quantities with given symmetries