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diff --git a/Source/FieldSolver/SpectralSolver/SpectralAlgorithms/SpectralBaseAlgorithm.H b/Source/FieldSolver/SpectralSolver/SpectralAlgorithms/SpectralBaseAlgorithm.H
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+++ b/Source/FieldSolver/SpectralSolver/SpectralAlgorithms/SpectralBaseAlgorithm.H
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+#ifndef WARPX_SPECTRAL_BASE_ALGORITHM_H_
+#define WARPX_SPECTRAL_BASE_ALGORITHM_H_
+
+#include <SpectralKSpace.H>
+#include <SpectralFieldData.H>
+
+/* \brief Class that updates the field in spectral space
+ * and stores the coefficients of the corresponding update equation.
+ *
+ * `SpectralBaseAlgorithm` is only a base class and cannot be used directly.
+ * Instead use its subclasses, which implement the specific field update
+ * equations for a given spectral algorithm.
+ */
+class SpectralBaseAlgorithm
+{
+    public:
+        // Member function that updates the fields in spectral space ;
+        // meant to be overridden in subclasses
+        virtual void pushSpectralFields(SpectralFieldData& f) const = 0;
+        // The destructor should also be a virtual function, so that
+        // a pointer to subclass of `SpectraBaseAlgorithm` actually
+        // calls the subclass's destructor.
+        virtual ~SpectralBaseAlgorithm() {};
+
+    protected: // Meant to be used in the subclasses
+
+        using SpectralCoefficients = amrex::FabArray< amrex::BaseFab <amrex::Real> >;
+
+        // Constructor
+        SpectralBaseAlgorithm(const SpectralKSpace& spectral_kspace,
+                              const amrex::DistributionMapping& dm,
+                              const int norder_x, const int norder_y,
+                              const int norder_z, const bool nodal)
+          // Compute and assign the modified k vectors
+          : modified_kx_vec(spectral_kspace.getModifiedKComponent(dm,0,norder_x,nodal)),
+#if (AMREX_SPACEDIM==3)
+            modified_ky_vec(spectral_kspace.getModifiedKComponent(dm,1,norder_y,nodal)),
+            modified_kz_vec(spectral_kspace.getModifiedKComponent(dm,2,norder_z,nodal))
+#else
+            modified_kz_vec(spectral_kspace.getModifiedKComponent(dm,1,norder_z,nodal))
+#endif
+          {};
+
+        // Modified finite-order vectors
+        KVectorComponent modified_kx_vec, modified_kz_vec;
+#if (AMREX_SPACEDIM==3)
+        KVectorComponent modified_ky_vec;
+#endif
+};
+
+#endif // WARPX_SPECTRAL_BASE_ALGORITHM_H_