I am trying to derive Heisenberg's equation of motion for an observable given by two Fermionic operators. The Hamiltonian has both Fermionic and Bosonic creation and annihilation operators.  

H := sum(g[`qαβ`]*C[alpha]*v[beta]*b[q]-g[`qαβ`]*B[q]*V[beta]*c[alpha], `qαβ`)

When I take the commutator with 

A := C[nu]*c[nu]

and try to simplify down it will only go so far. I know the final answer and have checked what it gives by hand, but it will not sum over the different indexes. 

Hello everyone, Greetings!

I am facing a really strange problem. I need to write an expression, however, maple out of nowhere assigns values to the variable used. only to those which are written inside sin (). In previous versions the out put is fine. Is there a new way to write expressions in maple 2019? I am not sure.

Download strngmpl.mw

Hi,

While trying to run this code :

pde := diff(u(x, t), t) = k*diff(u(x, t), x, x);
bc := u(x, 0) = T, u(0, t) = a*t + b, u(L, t) = T;
pdsolve([pde, bc], u(x, t)) assuming (0 < k, 0 < L, 0 < a, 0 < b, 0 < T, 0 <= t, 0 <= x and x <= L);

I get the following error :

Error, (in assuming) when calling 'factor'. Received: 'floating point coefficients are incompatible with field extension; use 'real' or 'complex' instead'

Any idea why ?

When I try to get a higher resolution plot using numpoints, the lines are jagged and look lower resolution.

You can see the difference, the first does not look anti-aliased whil ethe second does(although the 2nd looks far better on my comp)

Give the following functions find Domain, Range, Possible Asymptotes, Intercepts, Critical Points, Intervals of Increase, Decrease, Relative and Absolute Extrema, and Concavity.

A) f(x)=x(x^2-6x+8)

B) f(x) =x^3/4 -3x

Sorry,

I have been away from Maple for a year.
Then, when I used op command, I am puzzed to notice the results were different from those I know.

>op((x+5)^2*(x+y));
      _EXPSEQ((x+5)^2, x+y)

Result I know is 

        (x+5)^2, x+y

Has a modifire such as _EXPSEQ   automatically come to be attatched?
Or, can I have maple express it  in the form I know:  (x+5)^2, x+y?

Thank you in advance.

taro

Hi all, I would be most grateful if I could get some help with solving the tasks below using Maple.

Given the function: mx''(t)+cx'(t)+kx(t)= F_y(t)

1. Rewrite the equation above to a system of 1. order differential equations, by defining the two variables x_1(t) = x(t) and x_2(t)=x'(t) (Hint what is x'(t)?) This gives the first differential equation in the system. What is x_2'(t)?
    
2. Write the equations as a linear system when the outer force F_y(t) is the influence and the position x_1(t) is the answer, in other words give the system matrix A and the vectors b and r.
    
3. I'm given the constants m = 5kg, c = 3Ns/m and k = 20 N/m and I'm trying to find the transfer function of the system.
    
4. Give the systems transfer function H(s) and draw the graphs for the amplitude and phase characteristic.

Thank you!

how I can write a program code for newmark method.

in this method time has 3 order derivation

Why does this happen

interface(Typesetting)
                                         

interface(Typesetting=standard)
                                                      

interface(Typesetting)
                                            

a²

 We know the following facts: 

The SequenceGraph command returns a graph with the specified degree sequence given as input, if such a graph exists. It raises an exception otherwise. 
 But  If I  want to get more graphs  that satisfy this condition of degree sequence ? (If graphs are not many ,I want get all graphs better)
what should I do.?
For example: DrawGraph(SequenceGraph([3, 2, 2, 1, 1, 1]));  It returns the first graph below, but it is obvious that the second graph also fits the condition.

squenceGraph.mw

Hi

I have a first oder PDE, I use pdsolve I obtained a solution depend on function F

condition_unique_solution.mw

My question: The boundary condition  f(x,y) = 1 is supplied on the line y = k x, where k is a constant. For which k
does there exist a unique solution for f(x, y)?

Many thanks for your help

If I have checked the Editable button just below the working window, then the temperature would be very high in the next time when I start Maple 2019. I do not what is going on. But when I unchecked the Editable button, and wait for several seconds, then the temperature and the load of my laptop are on the normal state.  Is this a bug for Maple 2019? My OS is Debian Stretch, that is,

$ uname -a
Linux debian 4.9.0-9-amd64 #1 SMP Debian 4.9.168-1 (2019-04-12) x86_64 GNU/Linux

hye, can someone help me to solve nonlinear schrodinger equation using maple? i attach with document

solution_nonlinear.pdf

I'm new to Maple, and want to know what is the simpliest way to create additional electrical units like MVA and MVAr?

The help for the package Differential Geometry suggests one way to create an anholonomic frame, but the method suggested assumes one knows the frame and can write it in the coordinates of the manifold, and use this representation to compute the structure equations. It is useful to turn this problem around: suppose I know the structure equations but I do not know the frame, how do I correctly enter this in Maple so that later computations are correct?

Here is an example:

with(DifferentialGeometry): with(LieAlgebras):
DGsetup([x, y], R2):          
Fr := [A, B]; StructureEquations := [[A, B] = a(x, y)*A];
LD := LieAlgebras:-LieAlgebraData(StructureEquations, Fr, M);
DGsetup(LD, verbose):

that creates the Lie algebra M. I thought it would produce the manifold M whose frame {e1,e2} (or {A,B})) obeys the structure equations. But it does not. Indeed, the simple example

LieBracket(e1, f(x, y)*e2);

returns

f(x,y) a(x,y) e1.

The extra term where e1 differentiates f(x,y) does not appear. Just to be clear, the correct answer is

f(x,y) a(x,y) e1 + e1[f] e2.

How should I correctly setup this manifold?