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Ivancevic_Applied-Diff-Geom

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724 <strong>Applied</strong> <strong>Diff</strong>erential <strong>Geom</strong>etry: A Modern IntroductionThe SW solution is actually a special Ansatz for the functional form ofF(A) [Flume et. al. (1996)].4.14.1.4 Holomorphy and DualityIt is now easy to quantify what is meant by holomorphy and duality. Holomorphyis simply the statement that F(A) depends only on A and not on Ā.Duality means that the physics described by the effective action (4.209) isinvariant with respect to the duality transformation [Flume et. al. (1996)]:( ) A→A d( 0 1−1 0) ( AA d), D α W α → D ˙α W ˙α , τ(A) → (τ(A)) −1 .(4.210)Note that the duality transformation is closely linked to the Legendre transformof F(A) with respect to A. By noting that in the free classical theorywith θ o = 0 the transformation (4.210) reduces to⃗E → ⃗ B and g → 1 g ,we see that it is the generalization of the well–known Maxwell–Dirac duality.Thus the action (4.209) not only generalizes Maxwell–Dirac duality, butputs it into a genuine dynamical model. Furthermore, the duality (4.210)generalizes to( AA d)→( ) ( ) p q Ar s A dandτ(A) → pτ(A) + qrτ(A) + s ,where the matrix with entries (p, q, r, s) is in SL(2, Z). The integer–valuedness of the transformation follows from the requirement that, in theperturbation theory at least, it should change the θ angle only by multiplesof 2π and leaves the mass–formula form–invariant.4.14.1.5 The SW PrepotentialThe formulation of the SW solution [Seiberg and Witten (1994a); Seibergand Witten (1994b)] itself is relatively simple, as follows (see, e.g., [Marshakov(1997)]). Supersymmetry requires the metric on moduli space ofmassless complex scalars from N = 2 vector supermultiplets to be of ‘specialKähler form’, i.e., the Kähler potentialK(a, ā) = Im ∑ iā i∂F∂a i

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