than 1. In addition, various other parameters are given by the surface energy density and p$_{θ}$ and p$_{φ}$ are the surface pressures. The Lanczos equations now yield [7] 2 and To understand the dynamics of the wormhole, we assume the radius of the throat to be a function of proper time, or a = a ( τ ). Also, overdot and prime denote, respectively, the derivatives with respect to τ and a . For a static configuration of radius a , we obtain the respective values of the surface energy density and the surface pressures. For a static configeration of radius a , we obtain (assuming ˙ a = 0 and ¨ a = 0) from Eqs. (12) and (13), and where where m is the mass of the black hole. The parameters r$_{+}$ and r$_{−}$ are the inner and outer event horizons, re- spectively. Also, r = r$_{0}$ is a curvature singularity; the parameters obey the condition r$_{0}$ < r$_{−}$ < r$_{+}$ . In this paper we present a new kind of thin-shell worm- hole by surgically grafting two charged black holes in generalized dilaton-axion gravity. The exotic matter re- quired for its physical existence may possibly be collected from scalar fields that built the black holes. Various as- pects of this thin-shell wormhole are analyzed, particu- larly the equation of state relating pressure and density. Also discussed is the attractive or repulsive nature of the wormhole, as well as the energy conditions on the shell. Our final topic is a stability analysis to determine the conditions under which the wormhole is stable to lin- earized radial perturbations. A comparison to the stabil- ity of other thin-shell wormholes in the literature is also made. Observe that the energy density σ is negative. The pres- sure p may be positive, however. This would depend on the position of the throat and hence on the physical pa- rameters r$_{0}$ , r$_{−}$ , and r$_{+}$ defining the wormhole. Similarly, p + σ , σ + 2 p , and σ + 3 p , obtained by using the above equations, may also be positive under certain conditions, in which case the strong energy condition is satisfied. Keeping in mind the condition r$_{+}$ > r$_{−}$ > r$_{0}$ for dif- ferent radii defining the wormhole, we plot p versus a in Fig. 1. We choose typical wormholes whose radii ( r$_{0}$ , r$_{−}$ , and r$_{+}$ ) fall within the range 2 to 12 kms. Also taken into account is the sensitivity of the plots with respect to n , as described in the caption of the figure. The mathematical construction of our thin-shell worm- hole begins by taking two copies of the black hole and removing from each the four-dimensional region We now identify (in the sense of topology) the timelike hypersurfaces denoted by Σ. The resulting manifold is geodesically complete and consists of two asymptotically flat regions connected by a throat. The induced metric on Σ is given by where τ is the proper time on the junction surface. Using the Lanczos equations [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20], one can obtain the surface stress energy tensor S i j = diag( − σ, p$_{θ}$, p$_{φ}$ ), where σ is We now turn our attention to the attractive or repulsive nature of our wormhole. To perform the analysis, we calculate the observer’s four-acceleration a µ = u µ ; $_{ν}$u$^{ν}$, where u ν = dx $^{ν}$/dτ = (1 / √ f ( r ) , 0 , 0 , 0). In view of the line element, Eq. (2), the only non-zero component is given by D = 8 π ( a − r$_{0}$ ) 1 − $^{n}$( a + r$_{0}$ ) n √ ( a − r$_{−}$ )( a − r$_{+}$ ) . (16) p$_{θ}$ = p$_{φ}$ = p = 2 a − r$_{−}$ − r$_{+}$ D (15) σ = − 4[ a + (1 − 2 n ) r$_{0}$ ] D ( a − r$_{−}$ )( a − r$_{+}$ ) ( a r$_{0}$ )( a + r$_{0}$ ) (14) p$_{θ}$ = p$_{φ}$ = p = 1 8 π h $^{′}$( a ) h ( a ) √ f ( a ) + ˙ a 2 + 1 8 π 2¨ a + f $^{′}$( a ) √ f ( a ) + ˙ a $_{2}$. (13) σ = − 1 4 π h $^{′}$( a ) h ( a ) √ f ( a ) + ˙ a 2 (12) r$_{±}$ = m$_{0}$ ± √ m 2 0 + r 2 0 − 1 8 ( K$_{1}$ n + K$_{2}$ 1 − n ) , (5) r$_{0}$ = 1 16 m$_{0}$ ( K$_{1}$ n − K$_{2}$ 1 − n ) , (6) m$_{0}$ = m − (2 n − 1) r$_{0}$, (7) K$_{1}$ = 4 n [4 r 2 0 + 2 r$_{0}$ ( r$_{+}$ + r$_{−}$ ) + r$_{+}$r$_{−}$ ] , (8) K$_{2}$ = 4(1 − n ) r$_{+}$r$_{−}$, 0 < n < 1 , (9) m = 1 16 r$_{0}$ ( K$_{1}$ n − K$_{2}$ 1 − n ) + (2 n − 1) r$_{0}$, (10) Ω ± = { r ≤ a | a > r$_{+}$ } . ∂ Ω ± = { r = a | a > r$_{+}$ } , ds 2 = − dτ 2 + a ( τ ) $^{2}$( dθ 2 + sin $^{2}$θdφ$^{2}$) , (11) a r = Γ r tt ( dt dτ ) 2 = 1 2 Ar 2 − Br + C ( r − r$_{0}$ ) 3 2 $^{n}$( r + r$_{0}$ ) 2 n +1 (17) III. THE GRAVITATIONAL FIELD II. THIN-SHELL WORMHOLE CONSTRUCTION