PUBLICATIONS:    

 

BOOK:

G. Calvaruso and M. Castrillon-Lopez, Pseudo-Riemannian homogeneous structures, Developments in Math., 59, Springer, Cham, 2019, xv+230pp. ISBN: 978-3-030-18151-2; 978-3-030-18152-9.

 

PAPERS:
 

[1]. G. Calvaruso: Four-dimensional conformally flat Riemannian manifolds, Note di Matematica (2) 15 (1995), 153-159.

[2]. G. Calvaruso, Ph. Tondeur and L. Vanhecke: Four-dimensional ball-homogeneous and C-spaces, Beitrage Algebra Geom. (2) 38 (1997), 325-336.

[3]. G. Calvaruso and L. Vanhecke: Special ball-homogeneous spaces, Z. Anal. Anwendungen (4) 16 (1997), 789-800.

[4]. G. Calvaruso and L. Vanhecke: Semi-symmetric ball-homogeneous spaces and a volume conjecture, Bull. Austral. Math. Soc. (1) 57 (1998), 109-115.

[5]. G. Calvaruso, D. Perrone and L. Vanhecke: Homogeneity on three-dimensional contact metric manifolds, Israel J. Math. 114 (1999), 301-321.

[6]. G. Calvaruso and D. Perrone: Torsion and homogeneity on contact metric three-manifolds, Annali di Mat. Pura ed Appl. (4) 178 (2000), 271-285.

[7]. G. Calvaruso: Einstein-like and conformally flat contact metric three-manifolds, Balkan J. Geometry (2) 5 (2000), 17-36.

[8]. G. Calvaruso, R. A. Marinosci and D. Perrone: Three-dimensional curvature homogeneous hypersurfaces, Arch. Math. Brno (4) 36 (2000), 269-278.

[9]. G. Calvaruso and D. Perrone: Spectral geometry of the Jacobi operator of totally real submanifolds, Bull. Math. Soc. Roumanie, special number dedicated to the memory of Prof. G. Vranceanu, (3-4) 43 (93) (2000), 187-201.

[10]. G. Calvaruso and D. Perrone: On spectral geometry of minimal parallel submanifolds, Rend. Circolo Mat. Palermo Serie II 50 (2001), 103-116.

[11]. G. Calvaruso and D. Perrone: Semi-symmetric contact metric three-manifolds, Yokohama Mat. J. 49 (2002), 149-161.

[12]. G. Calvaruso: Totally real Einstein submanifolds of $CP^n$ and the spectrum of the Jacobi operator, Publ. Math. Debrecen (1-2) 64 (2002), 63-78.

[13]. G. Calvaruso: Spectral geometry of the Jacobi operator of totally real submanifolds of $QP^n$, Tokyo J. Math. (1) 28 (2005), 109-125.

[14]. G. Calvaruso and R. A. Marinosci: Homogeneous geodesics in five-dimensional generalized symmetric spaces,  Balkan J. Geom. (1) 8 (2002), 1-19.

[15]. G. Calvaruso, O. Kowalski and R. A. Marinosci, Homogeneous geodesics in solvable Lie groups, Acta Math. Hungarica (4) 101 (2003), 313-322.

[16]. E. Boeckx and G. Calvaruso, When is the unit tangent sphere bundle semi-symmetric?, Tohoku Math. J. (2) 56 (2004), 357-366.

[17]. G. Calvaruso, Conformally flat semi-symmetric spaces, Arch. Math. Brno 41 (2005), 27-36.

[18]. G. Calvaruso, Conformally flat pseudo-symmetric spaces of constant type, Czech. J. Math., 56 (131) (2006), 649-657.

[19]. G. Calvaruso, Contact metric geometry of the unit tangent sphere bundle, In: Complex, Contact and Symmetric manifolds, in Honour of L. Vanhecke, Progress in Math. 234 (2005), Birkhauser, Boston, Basel, Berlin, 41-57.

[20]. G. Calvaruso and D. Perrone, $H$-contact unit tangent sphere bundles, Rocky Mountain J.  Math., (5) 37 (2007), 1419-1442.

[21].  G. Calvaruso, Spectral geometry of totally complex submanifolds of $QP^n$, Kodai Math. J., (2) 29 (2006), 170-184.

[22]. M.T.K. Abbassi and G. Calvaruso, $g$-natural contact metrics on unit tangent sphere bundles, Monatsh. Math., 151 (2006),  89–109.

[23]. M.T.K. Abbassi and G. Calvaruso, The curvature tensor of $g$-natural metrics on unit tangent sphere bundles, Int. J. Contemp. Math. Sci., (6) 3 (2008), 245 – 258.

[24]. M.T.K. Abbassi and G. Calvaruso, Curvature properties of $g$-natural contact metric structures on unit tangent sphere bundles, Beitrage Algebra Geom., (1) 50 (2009), 155-178.

[25]. G. Calvaruso, Homogeneous structures on three-dimensional Lorentzian manifolds, J. Geom. Phys., (4) 57 (2007), 1279-1291.

[26]. G. Calvaruso and R.A. Marinosci, Homogeneous geodesics of three-dimensional unimodular Lorentzian Lie groups, Mediterr. J. Math., (3-4) 3 (2006), 467-481.

[27]. G. Calvaruso and R.A. Marinosci, Homogeneous geodesics of non-unimodular Lorentzian Lie groups and naturally reductive Lorentzian spaces in dimension three, Adv. Geom. 8 (2008), 473–489.

[28]. G. Calvaruso, Einstein-like metrics on three-dimensional homogeneous Lorentzian manifolds, Geom. Dedicata, 127 (2007), 99-119.

[29]. M.T.K. Abbassi, G. Calvaruso and D. Perrone, Harmonic sections of tangent bundles equipped with $g$-natural Riemannian metrics, Quart. J. Math. 62 (2011), 259–288.

[30]. M.T.K. Abbassi, G. Calvaruso and D. Perrone, Harmonicity of unit vector fields with respect to Riemannian g-natural metrics, Diff. Geom. Appl. 27 (2009) 157–169.

[31]. G. Calvaruso, Pseudo-Riemannian $3$-manifolds with prescribed distinct constant Ricci eigenvalues, Diff. Geom. Appl. 26 (2008) 419–433.

[32]. M.T.K. Abbassi and G. Calvaruso, $g$-natural metrics of constant curvature on unit tangent sphere bundles, Arch. Math. (Brno), to appear.

[33]. G. Calvaruso, Einstein-like Lorentz metrics and three-dimensional curvature homogeneity of order one, Canadian Math. Bull., 53 (2010), 412–424.

[34]. G. Calvaruso, Einstein-like curvature homogeneous Lorentz three-manifolds, Res. Math., 55 (2009), 295–310.

[35]. G. Calvaruso, Three-dimensional homogeneous Lorentzian metrics with prescribed Ricci tensor, J. Math. Phys., 48 (2007),  123518, 1-17.

[36]. G. Calvaruso, Three-dimensional semi-symmetric homogeneous Lorentzian manifolds, Acta Math. Hung., 121 (1-2) (2008), 157-170.

[37]. G. Calvaruso and J. Van der Veken, Parallel surfaces in three-dimensional Lorentzian Lie groups, Taiwanese J. Math., 14 (2010), 223-250.

[38]. G. Calvaruso and J. Van der Veken, Lorentzian symmetric three-spaces and their parallel surfaces, Int. J. Math., 20 (2009), 1185-1205.

[39]. G. Calvaruso and O. Kowalski, On the Ricci operator of locally homogeneous Lorentzian $3$-manifolds, Central Eur. J. Math., (1) 7 (2009), 124-139.

[40]. G. Calvaruso and B. De Leo, On the curvature of four-dimensional generalized symmetric spaces, J. Geom., 90 (2008), 30-46.

[41]. G. Calvaruso, Nullity index of Bochner-K\"{a}hler manifolds, Note Mat., 29 (2008), 117-124.

[42]. M.T.K. Abbassi, G. Calvaruso and D. Perrone, Harmonic maps defined by the geodesic flow, Houston J. Math., 36 (2010), 69-90.

[43]. M.T.K. Abbassi, G. Calvaruso and D. Perrone, Examples of naturally harmonic sections, Ann. Math. Blaise Pascal, 55 (2009), 295–310.

[44]. G. Calvaruso, Semi-symmetric Lorentzian metrics and three-dimensional curvature homogeneity of order one, Abh. Sem. Amburgh, 79 (2009), 1-10.

[45]. W. Batat, G. Calvaruso and B. De Leo, Curvature properties of Lorentzian manifolds with large isometry groups, Mathematical Physics, Analysis and Geometry, 12 (2009), 201–217.

[46]. G. Calvaruso and B. De Leo, Semi-symmetric Lorentzian three-manifolds admitting a parallel degenerate line field,  Mediterr. J. Math., 7 (2010), 89–100.

[47]. G. Calvaruso, Curvature homogeneous Lorentzian three-manifolds,  Ann. Glob. Anal. Geom., 36 (2009) , 1-17.

[48]. W. Batat, G. Calvaruso and B. De Leo, Homogeneous structures on Lorentzian three-manifolds admitting a parallel null vector field, Balkan J. Geom. Appl., 14, (2009), 11-20.

[49]. G. Calvaruso, D. Kowalcyk and J. Van der Veken, On extrinsic simmetries of hypersurfaces of H^n x R, Bull. Austral. Math. Soc., 82 (2010), 390-400.

[50]. G. Calvaruso and J. Van der Veken, Parallel surfaces in three-dimensional reducible spaces, Proc. Roy. Soc. Edinburgh, to appear.

[51]. G. Calvaruso, Conformally flat Lorentzian three-spaces with different properties of symmetry and homogeneity, Arch. Math. (Brno), 46 (2010), 119–134.

[52]. G. Calvaruso and B. De Leo, Pseudo-symmetric Lorentzian three-manifolds, Int. J. Geom. Meth. Mod. Phys., (7) 6 (2009), 1–16.

[53]. W. Batat, G. Calvaruso and B. De Leo, On the geometry of four-dimensional Walker manifolds, Rend. Mat., 29 (2008), 163–173.

[54]. M.T.K. Abbassi and G. Calvaruso, Harmonic maps having tangent bundles with $g$-natural metrics as source or target, Rend. Sem. Mat. Torino, 68 (2010), 37–56.

[55]. G. Calvaruso, Three-dimensional Ivanov-Petrova manifolds, J. Math. Phys., 50 (2009)  063509, 1–12.

[56]. G. Calvaruso and J. Van der Veken, Parallel surfaces in Lorentzian three-manifolds admitting a parallel null vector field, J. Phys. A: Math. Theor. 43 (2010) 325207 (9pp).

[57]. G. Calvaruso, General Riemannian $3$-metrics with a Codazzi Ricci tensor, Geom. Dedicata, (1) 151 (2011), 259-267.  

[58]. G. Calvaruso and E. Garcia-Rio, Algebraic Properties of Curvature Operators in Lorentzian Manifolds with Large Isometry Groups, SIGMA 6 (2010), 005, 1-8.

[59]. M. Brozos-Vazquez, G. Calvaruso, E. Garcia-Rio and S. Gavino-Fernandez, Three-dimensional Lorentzian homogeneous  Ricci solitons, Israel J. Math., 188 (2012), 385–403.

[60]. G. Calvaruso and D. Perrone, Homogeneous and  $H$-contact unit tangent sphere bundles, J. Austral. Math. Soc., 88 (2010), 323–337.

[61]. G. Calvaruso, Homogeneous paracontact metric three-manifolds, Illinois J. Math.,55 (2011), 697–718.

[62]. G. Calvaruso and D. Perrone, Contact pseudo-metric manifolds, Diff. Geom. Appl., 28 (2010) 615–634.

[63]. G. Calvaruso and B. De Leo, Ricci solitons on three-dimensional Walker manifolds, Acta Math. Hung., 132 (3) (2011), 269–293.

[64]. G. Calvaruso and D. Perrone, Harmonic morphisms and Riemannian geometry of tangent bundles, Ann. Glob. Anal.  Geom., 39 (2010), 187-213.

[65]. G. Calvaruso, Harmonicity properties of invariant vector fields on three-dimensional Lorentzian Lie groups, J. Geom. Phys., 61 (2011), 498–515.

[66]. G. Calvaruso and D. Perrone, Geometry of Kaluza–Klein metrics on the sphere S^3, Ann. Mat. Pura Appl., 192 (2013), 879–900.

[67]. G. Calvaruso and A. Fino, Five-dimensional $K$-contact Lie algebras, Monatsh. Math., 167 (2012), 35-59.

[68]. G. Calvaruso and A. Fino, Ricci solitons and geometry of four-dimensional non-reductive homogeneous spaces, Canadian J. Math., 64 (2012), 778–804.

[69]. G. Calvaruso, Three-dimensional paracontact Walker structures, Boll. U.M.I, Serie IX, 5 (2012), 387-403.

[70]. G. Calvaruso, Harmonicity of vector fields on four-dimensional generalized symmetric spaces, Central Eur. J. Math., 10 (2012), 411-425.

[71]. G. Calvaruso, Homogeneous contact metric structures on five-dimensional generalized symmetric spaces, Publ. Math. Debrecen, 81 (2012), 373-396.

[72]. G. Calvaruso and A. Fino, Complex and paracomplex structures on homogeneous pseudo-Riemannian four-manifolds, Int. J. Math. 24 (2013), 1250130, 1-28.

[73]. G. Calvaruso, Symplectic, complex and Kahler structures on four-dimensional generalized symmetric spaces, Diff. Geom. Appl., 29 (2011), 758–769.

[74]. G. Calvaruso and A. Fino, Four-dimensional pseudo-Riemannian homogeneous Ricci solitons, Int. J. Geom. Methods Mod. Phys.,  (5) 12  (2015), 1550056 (21 pp)

[75]. G. Calvaruso and A. Zaeim, Geometric structures over four-dimensional generalized symmetric spaces, Mediterr. J. Math., 10 (2013), 971–987.

[76]. G. Calvaruso and A. Zaeim, Four-dimensional homogeneous Lorentzian manifolds, Monatsh. Math., 174 (2014), 477-402.

[77]. G. Calvaruso, Four-dimensional paraKahler Lie algebras: classification and geometry, Houston J. Math., 41 (2015), 733-748.

[78]. G. Calvaruso and A. Zaeim, Geometric structures over non-reductive homogeneous 4-spaces, Adv. Geom., 14 (2014), 191-214.

[79]. G. Calvaruso and J. Van der Veken, Totally geodesic and parallel hypersurfaces of four-dimensional oscillator groups, Results Math., 64 (2013), 135–153.

[80]. G. Calvaruso and A. Zaeim, A complete classification of Ricci and Yamabe solitons of non-reductive homogeneous $4$-spaces, J. Geom. Phys, 80 (2014), 15–25.

[81]. G. Calvaruso and D. Perrone, Metrics of Kaluza-Klein type on the anti-de Sitter space H_1^3, Math. Nachr., 287 (2014), 885-902.

[82]. G. Calvaruso and A. Zaeim, Conformally flat homogeneous pseudo-Riemannian four-manifolds, Tohoku Math. J., 66 (2014), 31-54.

[83]. G. Calvaruso, Three-dimensional homogeneous almost contact metric structures, J. Geom. Phys., 69 (2013), 60–73.

[84]. G. Calvaruso, A. Fino and A. Zaeim, Homogeneous geodesics of non-reductive homogeneous pseudo-Riemannian $4$-manifolds, Bull. Brazil. Math. Soc, 46 (2015), 1-42.

[85]. G. Calvaruso and D. Perrone, H-Contact semi-Riemannian manifolds, J. Geom. Phys., 71 (2013) 11–21.

[86]. G. Calvaruso and A. Zaeim, Four-dimensional Lorentzian Lie groups, Diff. Geom. Appl., 31 (2013) 496–509.

[87]. G. Calvaruso and A. Perrone, Left-invariant hypercontact structures on three-dimensional Lie groups, Period. Math. Hung., 69 (2014), 97-108.

[88]. G. Calvaruso and D. Perrone, Geometry of H-paracontact metric manifolds, Publ. Math. Debrecen, 86 (2015), 325–346.

[89]. G. Calvaruso and V. Martin-Molina, Paracontact metric structures on the unit tangent sphere bundle, Ann. Mat. Pura Appl., 194 (2015), 1359-1380.

[90]. G. Calvaruso and A. Perrone, Classification of 3D left-invariant almost paracontact metric structures, Adv. Geom., 17 (2017), 265-282.

[91]. G. Calvaruso and A. Zaeim, Left-invariant neutral metrics on four-dimensional Lie groups, J. Lie Theory, 25 (2015), 1023-1044.

[92]. G. Calvaruso and A. Perrone, Natural almost contact structures and their 3D homogeneous models, Math. Nachr., 289 (2016), 1370-1385.

[93]. G. Calvaruso and M.I. Munteanu, Hopf magnetic curves in the anti-de Sitter space $H_1^3$, J. Nonlin. Math. Phys., 25 (2018), 463-485.

[94]. G. Calvaruso and A. Zaeim, Invariant symmetries on non-reductive homogeneous pseudo-Riemannian four-manifolds,  Rev. Mat. Complut., 28 (2015), 599-622.

[95]. G. Calvaruso, M.I. Munteanu and A. Perrone, Killing magnetic curves in three-dimensional almost paracontact manifolds, J. Math. Anal. Appl., 426 (2015), 423-439.

[96]. G. Calvaruso and M. Castrillon-Lopez, Cyclic Lorentzian Lie groups, Geom. Dedicata, 181 (2016), 119-136.

[97]. G. Calvaruso and A. Perrone, Ricci solitons in three-dimensional paracontact geometry, J. Geom. Phys., 98 (2015), 1-12.  

[98]. G. Calvaruso and A. Zaeim, On the symmetries of the Lorentzian oscillator group, Collectanea Math., 68 (2017), 51-67 .

[99]. G. Calvaruso and A. Perrone, Five-dimensional paracontact Lie algebras, Diff. Geom. Appl., 45 (2016), 115–129.

[100]. G. Calvaruso, Oscillator spacetimes are Ricci solitons, Nonlinear Anal., 140 (2016), 254-269.

[101]. G. Calvaruso and A. Zaeim, Symmetries of Lorentzian three-manifolds with recurrent curvature, SIGMA Symmetry, integrability, Geometric Methods and Applications, 12 (2016), n. 63, 12pp.

[102]. G. Calvaruso and A. Perrone, Cosymplectic and \alpha-cosymplectic Lie algebras, Complex Manifolds 3 (2016), 252-270.

[103]. G. Calvaruso and E. Rosado, Ricci solitons on low-dimensional generalized symmetric spaces, J. Geom. Phys., 112 (2017), 106-117.

[104]. G. Calvaruso, Three-dimensional homogeneous generalized Ricci solitons, Mediterr. J. Math., 14 (2017), n. 216, 21pp.

[105]. G. Calvaruso and G. Ovando, From almost (para-)complex structures to affine structures on Lie groups, Manuscripta Math., 155 (2018), 89-113.

[106]. G. Calvaruso and A. Zaeim, Four-dimensional pseudo-Riemannian g.o. spaces and manifolds, J. Geom. Phys. , 130 (2018), 63-80.

[107]. M.T.K. Abbassi, N. Amri and G. Calvaruso , Kaluza-Klein type Ricci solitons on unit tangetn sphere bundles, Diff. Geom. Appl., 59 (2018), 184-203.

[108]. G. Calvaruso, The Ricci soliton equation and the structure of homogeneous Godel spacetimes, J. Math. Anal. Appl., 465 (2018), 1112-1133.

[109]. G. Calvaruso, Siklos spacetimes as homogeneous Ricci solitons, Class. Quantum Grav., 36 (2019), 095011 (13pp.).

[110]. G. Calvaruso, G. Metafune, L. Negro and C. Spina, Optimal kernel estimates for elliptic operators with second order discontinuous coefficients, J. Math. Anal. Appl., 485 (2020), 123763 (16pp.).

[111]. G. Calvaruso, R. Storm and J. Van der Veken, Parallel and totally geodesic hypersurfaces of non-reductive homogeneous four-manifolds, Math. Nachr. 293 (2020), 1707-1729.

[112]. G. Calvaruso, F. Esposito and D. Perrone, Levi flat CR-structures on 3D Lie algebras, Annali Mat. Pura Appl.,199 (2020), 2521-2542.

[113] M.T.K. Abbassi, N. Amri and G. Calvaruso, g-natural symmetries on tangent bundles, Math. Nachr., 293 (2020), 1873-1887.

[114]. G. Calvaruso and A. Zaeim, Homogeneous geodesics and natural reductivity of homogeneous Godel-type spacetimes, J.
Geom. Phys., 159(2021), 103919 (11pp.).

[115]. G. Calvaruso, On semi-direct extensions of the Heisenberg group, Collectanea Math., 72 (2021), 1-23.

[116]. A. Arvanitoyeorgos, G. Calvaruso and N. Souris, Two-step homogeneous geodesics in pseudo-Riemannian manifolds, Ann. Global Anal. Geom., 59 (2021), 297-317.

[117]. G. Calvaruso, Solutions of the Ricci soliton equation for a large class of Siklos spacetimes, Int. J. Geom. Methods Mod. Phys. 18 (2021), 2150052 (19 pp.).

[118]. G. Calvaruso, The Ricci soliton equation for homogeneous Siklos spacetimes, Note Mat. 41 (2021), 31-44.

[119]. G. Calvaruso and A. Zaeim, Conformal Geometry of semi-direct extensions of the Heisenberg group, J. Math. Phys. Anal. Geom., 17 (2021), no. 4, 407-421.

[120]. G. Calvaruso, M. Kaflou and A. Zaeim, On the symmetries of Siklos spacetimes, Gen. Relativity Gravitation 54 (2022), Paper No. 60, 26 pp.

[121]. G. Calvaruso and A. Zaeim, Critical metrics for quadratic curvature functionals on some solvmanifolds, Revista Mat. Complut. 36 (2023), 869-886.

[122]. G. Calvaruso, Einstein-like metrics on three-dimensional non-unimodular Lorentzian Lie groups, Bull. Iranian Math. Soc. 49 (2023), Paper No. 14, 14 pp.

[123]. M.T.K. Abbassi, K. Boulagouaz and G. Calvaruso, On the Geometry of the Null Tangent Bundle of a Pseudo-Riemannian Manifold,Axioms 12 (2023), Paper No. 903, 55pp.

[124]. G. Calvaruso, I. Onnis, L. Pellegrino and D. Uccheddu, Helix surfaces for Berger-like metrics on the anti-de Sitter space,Rev. R. Acad. Cienc. Exactas Fis. Nat. Ser. A Mat. (RACSAM) 118 (2024), Paper No. 54.

[125]. G. Calvaruso, L. Pellegrino and J. Van der Veken, Totally geodesic and parallel hypersurfaces of Gödel-type spacetimes J. Geom. Phys. 198 (2024), Paper No. 105108.

 

PROCEEDINGS OF CONFERENCES:



[a]. G. Calvaruso e L. Vanhecke: Ball-homogeneous spaces, Public. Dep.to de Geometria y Topologia, Univ. Santiago de Compostela (Spain), Proceedings of the Workshop on “Recent Topics in Differential Geometry”, 89 (1998), 35-51.

[b]. G. Calvaruso: Homogeneity on contact metric three-manifolds, Proceedings of the IV International Workshop in Differential Geometry, Brasov (Romania) (1999), 18-25.

[c]. G. Calvaruso: Spectral rigidity of closed minimal submanifolds, An. Univ. Timisoara Ser. Mat.-Inform. 39 (2001), Special issue: Mathematics, Proceedings of the V International Workshop in Differential Geometry, Timisoara (Romania), 2001, 123-134.

[d]. G. Calvaruso: Conformally flat semi-symmetric spaces, In: D. Andrica and P.A. Blaga (Eds.), Recent advances in Geometry and Topology, Proceedings of the VI International Workshop in Differential Geometry, Cluj-Napoca (Romania), 2003, Cluj Univ. Press, 123-129.

[e]. G. Calvaruso: Symmetry conditions on conformally flat Riemannian manifolds, Differential geometry and its applications, 19–27, Matfyzpress, Prague, 2005.

[f]. G. Calvaruso and R.A. Marinosci, Homogeneous geodesics of three-dimensional Lorentzian Lie groups. XV International Workshop on Geometry and Physics, 252–259, Publ. R. Soc. Esp., R. Soc. Mat. Esp., Madrid, 2007.

[g]. G. Calvaruso e Z. Dusek, A n.g.o. space whose geodesics need a reparametrization, Geometry, integrability and quantization, 167–174, Softex, Sofia, 2008.

[h]. G. Calvaruso, On the geometry of $g$-natural contact metric structures on the unit tangent sphere bundle, Pure and applied differential geometry—PADGE 2007, 23–31, Ber. Math., Shaker Verlag, Aachen, 2007.

[i]. G. Calvaruso, Naturally Harmonic Vector Fields, Note di Matematica 28, suppl. n. 1, 2009, 101–124.

[j].G. Calvaruso, Constructing metrics with prescribed geometry, Harmonic maps and differential geometry, 177–185,Contemp. Math. 542, Amer. Math. Soc., Providence, RI, 2011.

[k]. G. Calvaruso, Contact Lorentzian manifolds, Differential geometry and its applications, 29 (2011), S41–S51.

[l]. G. Calvaruso, On the geometry of four-dimensional Lorentzian Lie groups, Pure and applied differential geometry—PADGE 2012, 46–54, Ber. Math., Shaker Verlag, Aachen, 2013.

[m].  G. Calvaruso and V. Martin-Molina, Recent advances in paracontact metric geometry, Int. J. Geom. Meth. Mod. Phys., 11 (2014), 1460038, 8 pp.

[n]. G. Calvaruso, A complete classification of four-dimensional paraKahler Lie algebras, Complex Manifolds, 2 (2015), 1-10.

[o]. G. Calvaruso, Harmonicity properties of paracontact metric manifolds, Rend. Semin. Mat. Univ. Politec. Torino, 73 (2015), 37-50.

[p]. G. Calvaruso, The prescribed curvature problem in low dimension, Geometry, algebra and applications: from mechanics to cryptography, Springer Proc. Math. Stat. 161, 37-48.

[q]. G. Calvaruso, Four-dimensional pseudo-Riemannian Lie groups, Rend. Semin. Mat. Univ. Politec. Torino, 74 (2016), 31-43.