Functional Analysis, Operator Theory, Abstract Differential Equations, Nonlinear analysis. 

Research gate: https://www.researchgate.net/profile/Sachi-Srivastava

• Chill, R., Sharma, P., & Srivastava, S. (2025). Reiteration theorems for the interpolation of quasi-subadditive functions on Banach spaces. Mathematische Nachrichten, 298(7), 2242-2262. https://doi.org/10.1002/mana.12025 

• Pappu, Rastogi, S. & Srivastava, S. Eventual positivity, perturbations and delay semigroups. Positivity 29, 12 (2025). https://doi.org/10.1007/s11117-024-01105-9 

• Kumar, D., Srivastava, S. Quantum extensions of classical Jacobi semigroups. Semigroup Forum 109, 513–536 (2024). https://doi.org/10.1007/s00233-024-10481-3 

• Anand, J., Lata, S. & Srivastava, S. Weighted and Unweighted Composition Operators Close to Isometries. Mediterr. J. Math. 21, 144 (2024). https://doi.org/10.1007/s00009-024-02688-z .

• Ralph Chill, Praveen Sharma, Sachi Srivastava. Real interpolation of functions with applications to accretive operators on Banach spaces, Journal of Differential Equations, Volume 402, (2024), Pages 554-592, https://doi.org/10.1016/j.jde.2024.05.024.

• Sahiba Arora, Ralph Chill, Sachi Srivastava. Domination of Semigroups on standard forms of von Nuemann Algebras Arch. Math.121, 715-729 (2023). https://doi.org/10.1007/s00013-023-01946y.

• Dharmendra Kumar, Kalyan B. Sinha, Sachi Srivastava. Quantum dynamical semigroups and stability. J. Math. Anal. Appl. 516 (2022), no. 1, Paper No. 126492, 21 pp. https://doi.org/10.1016/j.jmaa.2022.126492

• Jatin Anand and Sachi Srivastava. A Class of Invariant Subspaces of weighted composition operators on Hardy-Hilbert Spaces. Anal. Math. 48 (2022), no. 4, 925-937. https://doi.org/10.1007/s10476-022-0134-x .

• Jatin Anand, Niteesh Sahani and Sachi Srivastava. On extension of Beurling Helson Lowdenslager theorem. Advances in Operator Theory. 6(4) 2021.  http://dx.doi.org/10.1007/s43036-021-00158-x

• Franco Fagnola, Dharmendra Kumar and Sachi Srivastava. A Quantum Laugerre Semigroup. Indian Journal of Pure and Applied Mathematics. 52, (2021), 1201-1200. https://doi.org/10.1007/s13226-021-00029-4 

• Shard Rastogi and Sachi Srivastava. Strong and Polynomial Stability for Delay Semigroups. Journal of Evolution Equations. 21(2021), no. 1, 441-472. https://doi.org/10.1007/s00028-020-00588-9 

• Dharmendra Kumar, Kalyan B. Sinha and Sachi Srivastava. Stability of the Markov (Conservativity) Property under Perturbations. Infin. Dimens. Anal. Quantum Probab. Relat. Top. 23 (2020), no. 2, 2050009, 20 pp. https://doi.org/10.1142/S0219025720500095

• Abhay Kumar and Sachi Srivastava. Supercyclicity Criteria for C0-Semigroups. Adv. Oper. Theory 5 (2020), no. 4, 1646-1666. https://doi.org/10.1007/s43036-020-00073-7 

• Anand, J., Bhattacharyya, T. and Srivastava, S. Some thoughts on composition operators on subspaces of the Hardy space. Arch. Math. (Basel) 114, no. 4, 431-444, 2020.  https://doi.org/10.1007/s00013-019-01406-6 

• Isabelle Chalendar, Wolfgang Arendt, Mahesh Kumar and Sachi Srivastava. Powers of composition operators: Asymptotic behaviour on Bergman, Dirichlet and Bloch spaces J. Aust. Math. Soc. 108, no. 3, 289-320, 2020.  https://doi.org/10.1017/S1446788719000235

• Tarachand Prajapati, K.B. Sinha and Sachi Srivastava. Lyapunov property of positive C0 semigroups on non-commutative Lp spaces. Operators and Matrices, Volume 13, Number 4 (2019), 907-919.  http://dx.doi.org/10.7153/oam-2019-13-64

• Abhay Kumar and Sachi Srivastava. Supercyclic C0 semigroups, stability and somewhere dense orbits. Journal of Mathematical Analysis and Applications, 476, 539-548, 2019. https://doi.org/10.1016/j.jmaa.2019.03.067

• Shard Rastogi and Sachi Srivastava. Non-analytic growth bound and delay semigroups. Semigroup Forum 99, no. 3, 788-813, 2019.  https://doi.org/10.1007/s00233-019-10010-7 

• Mahesh Kumar and Sachi Srivastava. Convergence of powers of composition operators on certain spaces of Holomorphic functions defined on the right half plane. Archiv der Mathematik,110(5), 487-500, 2018.  https://doi.org/10.1007/s00013-018-1159-z 

• Isabelle Chalendar, Wolfgang Arendt, Mahesh Kumar and Sachi Srivastava. Asymptotic behaviour of powers of composition operators on Banach spaces of Holomorphic functions. Indiana Univ. Math. J. 67 (2018), 1571-1595. http://dx.doi.org/10.1512/iumj.2018.67.7389

•  K.B. Sinha and Sachi Srivastava. Theory of Semigroups and Applications. TRIM series, Hindustan Book Agency, 2017. Electronic version published by Springer.

• Sharad Rastogi and Sachi Srivastava. Quasi-hyperbolicity and delay semigroups. Abstract and Applied Analysis. Article ID 1984874. 2016. https://doi.org/10.1155/2016/1984874

• C.J.K. Batty, R. Chill and S. Srivastava. Maximal Regularity for some Interpolation Sapces. Operator semigroups meet Complex Analysis, Harmonic Analysis and Mathematical Physics Operator Theory: Advances and Applications, Vol 250, 49-66, Birkhauser, 2015.

• B.V.R. Bhat and S. Srivastava. Stability of Quantum dynamical semigroups. Operator semigroups meet Complex Analysis, Harmonic Analysis and Mathematical Physics Operator Theory: Advances and Applications, Vol 250, 67-85, Birkhauser, 2015. 

• C.J.K.Batty, R. Chill and S.Srivastava. Maximal regularity for certain non-autonomous second order Cauchy problems. Studia Mathematica. no. 256, (2008), 205 - 223.

• R. Chill and S. Srivastava. Lp Maximal regularity for second order Cauchy problems is independent of p. Boll. Unione Mat. Ital., Series IX, Vol. 1 - 1, (2008), 147 - 158.

• R. Chill and S. Srivastava. Lp Maximal regularity for second order Cauchy problems. M. Zeitschrift, 251 (2005), No. 4,751 -781. https://doi.org/10.1007/s00209-005-0815-8 

• C.J.K. Batty and S. Srivastava. The non-analytic growth bound of a C0 semigroup and inhomogeneous Cauchy problems. Journal of Differential Equations, 194 (2003) 300-327. https://doi.org/10.1016/S0022-0396(03)00195-5

• C.J.K. Batty, M. Blake and S. Srivastava. A non-analytic growth bound for semigroups of operators and Laplace transforms. Integral Equations and Operator Theory, Vol. 45 (2003), No. 2, 1251-54. http://dx.doi.org/10.1007/s000200300000

• Feb 2017 onwards. Professor, Department of Mathematics, University of Delhi, Delhi

•  Feb 2010 - Feb 2017. Associate Professor, Department of Mathematics University of Delhi, Delhi.

•  Feb 2007 - Jan 2010. Reader, Department of Mathematics University of Delhi, Delhi.

• Jul 2002 to Jan 2007. Senior Lecturer, Department of Mathematics Lady Shri Ram College, University of Delhi.

• Jul 1995 to Jul 2002. Lecturer, Department of Mathematics Lady Shri Ram College, University of Delhi. (On study leave from Oct 1998 to July 2002)

• 2002, DPhil in Mathematics St. Johns College, University of Oxford

Supervisor: C.J.K. Batty

Thesis Title: Laplace transforms,non-analytic growth bounds and C0-semigroups

• 1996, M.Phil in Mathematics, University of Delhi

Supervisor: Ajit Iqbal Singh

Thesis Title: Second Dual of a group algebra, First Class with Distinction.

• 1994, M.A. in Mathematics, Lady Shri Ram College, Univ. of Delhi

Aggregate marks: 93%

2nd Position in the University in M.A./M.Sc.

•  1992, B.A.(Hons) in Mathematics, Lady Shri Ram College, Univ. of Delhi

Aggregate marks: 92.3%

2nd Position in the University in B.A./B.Sc. (Hons)

• Indian National Science Academy Teachers Award 2020.

• Commonwealth Research Award Association of Commonwealth Universities, UK, 1998.

• National Board for Higher Mathematics Research Award Department of Atomic Energy, Government of India, 1994.

• National Board for Higher Mathematics Award for Masters program Department of Atomic Energy, Government of India, 1992.

• 1991 - 1994 Best Student in Mathematics (four consecutive years), Lady Shri Ram College.

• 2nd Position in Allahabad in ISC Class XII examinations, 1989 with 93% aggregate marks.

• July 2022, Invited Visitor, Department of Mathematics, Newcastle University, Newcastle, UK.

• March 2019 to May 2019, Invited Visitor, Department of Mathematics, University of California, Berkeley, USA.

•  June 2015. Invited Visitor, Mathematical Institute, University of Oxford, UK.

• Dec 2005 to Nov 2006, Research Associate, Department of Mathematics Indian Institute of Science, Bangalore. (On academic leave from Lady Shri Ram College )

• April 2005 to May 2005, Invited Visitor, Department of Mathematics, University of Berkeley, USA.

•  May 2004 to July 2004, Invited Visitor, Mathematical Institute, University of Oxford, UK.

• May 2003 to July 2003. Visiting research scholar, Department of Applied Analysis, University of Ulm, Germany.

• Member, Executive Committee, Ramanujan Mathematical Society, 2022 -

• Convener, Research Publications Committee, Ramanujan Mathematical Society, 2022 -

• Member, Executive Committee, Indian Women in Mathematics, NBHM sponsored project, 2016-

• Member, American Mathematical Society and Ramanujan Mathematical Society.

• Mahesh Kumar. Asymptotics of composition operators on Banach spaces of holomorphic functions. May 2019.

• Shard Rastogi. Operator Semigroups for Delay Differential Equations. October 2019.

• Abhay Kumar. Supercyclic C0 semigroups. 2021.

• Tarachand Prajapati. Operator semigroups on non-commutative Lp spaces. August 2021.

•  Dharmendra Kumar.Conservativity, Stability and Perturbations of Quantum Dynamical Semigroups. April 2022.

•  Jatin Anand. Composition Operators and Invariant subspaces. March 2022.

• Pappu Anuragi. Positive C0-semigroups. (Ongoing)

• Praveen Sharma. Non-linear Semigroups. (Ongoing)

•  Pooja. (ongoing)

• Sahiba Arora. Eventually positive C0 semigroups. March 2019.

• Himani Sharma. Semigroups of Composition Operators. December 2017.

• Geeta. Isometries and Semigroups of Isometries on Hilbert C* Modules. August 2017.

• Reena. Quasi Hyperbolic Semigroups of Operators. December 2016.

• Rachna Shokhanda. Cayley Transform of the Generator of a C0 Semigroup. Oct 2015.

• Mahesh Kumar. Norm Continuity of C0 Semigroups, June 2011.