Recent content by y35dp

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    Graduate The Klein-Gordon field as harmonic operators

    I am reading through 'An Introduction to QFT' by Peskin & Schroeder and I am struggling to follow one of the computations. I follow writing the field \phi in Fourier space ϕ(x,t)=∫(d^3 p)/(2π)^3 e^(ip∙x)ϕ(p,t) And the writing the operators \phi(x) and pi(x) as ϕ(x)=∫(d^3 p)/(2π)^3...
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    Solution to Operators Problem Using the Operator Expansion Theorem

    Hero
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    Solution to Operators Problem Using the Operator Expansion Theorem

    Homework Statement Use the operator expansion theorem to show that Exp(A+B) = Exp(A)\astExp(B)\astExp(-1/2[A,B]) (1) when [A,B] = \lambda and \lambda is complex. Relationship (1) is a special case of the Baker-Hausdorff theorem. Homework Equations Operator expansion theorem...
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    Undergrad Understanding Summation Notation

    Thank you, you may just have rescued my mental health
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    Undergrad Understanding Summation Notation

    I know this should be easy and the answer will be glaringly obvious in hindsight but my brain is fried and I can't for the life of me figure this out. My problem is this I have a function as follows; V = \sum\lambdai,j,k hihjhk (summation over i,j,k where i,j,k = 1,2,3) I can't work...
    • y35dp
    • Thread
    • Notation Summation
    • Replies: 2
    • Forum: Calculus
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    How to Construct Gamma Matrices in Higher Dimensions Using Sigma Matrices?

    Sorry those \sigma1,\sigma2,\sigma3 are supposed to be the Pauli matrices, pretty poor attempt at making matrices on my part
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    How to Construct Gamma Matrices in Higher Dimensions Using Sigma Matrices?

    Homework Statement If D =7 and the metric g\mu\nu=diag(+------), Using the outer product of matrices, A \otimes B construct a suitable set of \gamma matrices from the 2 x 2 \sigma-matrices Homework Equations \sigma1=(0, 1 ) \sigma2=(0, -i)...
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    Is (1-Exp[-i x])^2 equal to Sin^2(x) in particle physics?

    ok this confirms my thoughts that the two aren't equal this is a particle physics problem but i though the issue was my algebra but the issue must be with my physics!
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    Is (1-Exp[-i x])^2 equal to Sin^2(x) in particle physics?

    start point (1-Exp[-i x])^2, (i^2 = -1) finish point Sin^2(x)