#### Abstract

Using the Schauder fixed point theorem, we prove the existence of impulsive fractional differential equations using Hilfer fractional derivative and nearly sectorial operators in this paper. We’ve gone over the two scenarios where the related semigroup is compact and noncompact for this purpose. We also go over an example to back up the main points.

#### 1. Introduction

We consider the following impulsive fractional differential equations involving Hilfer fractional derivative and almost sectorial operatorswhere Hilfer fractional derivative of order and type and is an almost sectorial operator in having norm and denotes the jump of at , i.e., , where and . and . is a function which is defined later.

In fact, rapid changes in the dynamics of evolutionary processes might occur due to shocks, harvesting, or natural disasters, among other things. These short-term disturbances are frequently handled as impulses. Hilfer derivative fractional differential equations have recently gained a lot of attention in the literature. [1–12] appears to be the case.

In [3], Anjali Jaiswal and Bahuguna studied the equations of Hilfer fractional deritaive with almost sectorial operator in the abstract sense.

We also refer to Hamdy M. Ahmed et.al studied in [13], which looked at the existence of nonlinear Hilfer fractional derivative differential equations with control. Sufficient circumstances have been found where the Hilfer derivative is the time fractional derivative. In [14], Yong Zhoy et.al studied the factional cauchy problems with almost sectorial operators of the formwhere is Riemann–Liouville derivative of order §, is Riemann–Liouville integral of order , . is an almost sectorial operator on a complex Banach space, and is a given function.

The paper is structured as follows: we have presented some information in section 2 about Hilfer derivative, almost sectorial operators, measure of non-compactness, mild solutions of equations along with some basic definitions, results and lemmas. We discuss the main results for mild solutions for the equations in section 3. In section 4 5, we have discussed the two cases if associated semigroup is compact and noncompact respectively. Finally, an example is discussed to illustrate the main result.

The following sections describes the supporting results of the given problem and also generalizes the results in [14–16].

#### 2. Preliminaries

*Definition 1. *(see [17]). For , the fractional integral of order § of a function is defined by

*Definition 2. *(see [17]). For , the Riemann-Liouville (R-L) fractional derivative with order § of a function is defined by

*Definition 3. *(see [17]). For , the Caputo fractional derivative with order § of a function is defined by

*Definition 4. *(see [11]). Let and . The Hilfer fractional derivative derivative of order § and type is defined by

##### 2.1. Measure of Non-compactness

Let also bounded. The Hausdorff measure of non-compactness is considered as follows

The Kurtawoski measure of noncompactness on a bounded set is considered as followswith the following properties1. gives where are bounded subsets of 2. iff is relatively compact in 3. for all 4.5.6. for .

Let and . We define

##### 2.2. Almost Sectorial Operators

Let and . We define and its closure by , that is .

*Definition 5. *(see [18]). For , we define as a family of all closed and linear operators this implies1. is contained in .2.For all , there exists implieswhere is the resolvent operator and is said to be an almost sectorial operator on .

We assume the following Wright-type function [17]For ,(A1);(A2);(A3).We have define , by

Theorem 1 (Theorem 4.6.1 in [17]). *For each fixed and are bounded and linear operators on . Alsowhere and are constants.*

We introduce the following hypotheses to obtain our main results.(H1)For is continuous function and for each is strongly measurable.(H2) a function satisfying(H3) for and , where .(H4) constants such that for each .

Lemma 1. *The fractional Cauchy problem is equivalent to an integral equation given by*

Lemma 2. *Let £ is a solution of the integral equation given in (2.3), then £ satisfieswhere .*

*Definition 6. *By a mild solution of the Cauchy problem we mean a function that satisfiesNow, we define an operator as

Lemma 3 (see [3]). * and are bounded linear operators on , for every fixed . Also for .*

Proposition 1 (see [3]). * and are strongly continuous, for .*

#### 3. Main results

Theorem 2. *Let for and . Assuming are satisfied, the operators is equicontinuous provided with .*

*Proof. *For and , we gave, as .

Now, let ,here, using the triangle inequality, we haveSince the strong continuous of , we get as . AlsoThen as , by using and the dominated convergence theorem. Sinceand exists, i.e, as .

For , we haveSince is uniformly continuous and , then as i.e. independent of .

Clearly, since the strongly continuous of of , we getHence independently of as therefore is equicontinuous.

Theorem 3. *Let and and . Then under consideration the operator is continuous and bounded provided with .*

*Proof. *We verify that maps . Taking and define , we have . Let ,From , we getHence , for any .

Now, to verify is continuous in , let , with . That is and and , on .

impliesas .

From to obtain the inequality ,

i.e.,Let . Now,Applying Theorem 1, we have as , i.e, pointwise on . Also Theorem 2 implies that uniformly on as . That is is continuous.

#### 4. is Compact

Theorem 4. *Let and . If is compact and hold then a mild solution of in for every with .*

*Proof. *Since we have assumed is compact, then the equicontinuity of . Moreover, by Theorem 2 and 3, is continuous and bounded and is bounded, continuous and equicontinuous. We can write bywhere