powm function does not give the correct answer

[LiangtaoPeng]

When I use the powm function, I found sometimes it does not return the correct answer. For example

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-0.026961480176208127 -0.026953307326782507 -0.026938274803406468 -0.026905854308464327 -0.0268136528481272 -0.026326486065100668 3.850631961339304 -0.026326486065100668 -0.0268136528481272 -0.026905854308464327 -0.026938274803406468 -0.026953307326782507 -0.026961480176208127 -0.026966410542349193 -0.02696961150469324 -0.02697180651307083 -0.026973376808854362 -0.02697453876784025 -0.026975422599970964 -0.02697611046927254 -0.026976656297467955 -0.0269770966599012 -0.026977457074983148 -0.02697775578548294 -0.026978006112881783 -0.026978217968578966 -0.026978398850170903 -0.026978554513979264 -0.02697868943870928 -0.026978807151213847 -0.02697891045931534 -0.026979001620799647; -0.033442230440465986 -0.033436116076806556 -0.033425980567172546 -0.0334073380745036 -0.03336713199438233 -0.03325278891269189 -0.03264863198215313 3.850631961339304 -0.03264863198215313 -0.03325278891269189 -0.03336713199438233 -0.0334073380745036 -0.033425980567172546 -0.033436116076806556 -0.033442230440465986 -0.03344620009449809 -0.03344892222082138 -0.033450869613611024 -0.033452310609998266 -0.03345340668905334 -0.03345425974599468 -0.03345493665151992 -0.03345548276432002 -0.033455929730897414 -0.033456300174911593 -0.033456610616916634 -0.033456873348474254 -0.033457097667683164 -0.033457290713210755 -0.033457458039296166 -0.03345760401974458 -0.03345773213665993; 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using IterativeSolvers
powm(kernel)[1]

This code block return

4.4819149212347265 + 4.8907651174712186e-5im

But this is not the largest absolute eigenvalue, we can check this by

using LinearAlgebra
maximum(eigvals(kernel))

which gives

4.620407037613936

Julia 1.8, IterativeSolvers v0.9.2