How to execute dynamically created assembly in a given application domain?

I have a problem trying to execute a dynamic assembly in a given application domain. The assembly is building using System.Reflection.Emit.AssemblyBuilder class as shown

    // Utility method for building 'MathClient' assembly in memory. 
    public static void CreateMathClient(AppDomain domainForAssembly)
    {
        // Assembly name... 
        AssemblyName assemblyName = new AssemblyName();
        assemblyName.Name = "MathClient";
        assemblyName.Version = new Version("1.0.0.0");

        AssemblyBuilder assembly = domainForAssembly.DefineDynamicAssembly(
            assemblyName, AssemblyBuilderAccess.RunAndSave);
        ModuleBuilder module = assembly.DefineDynamicModule(
            "MathClient", "MathClient.exe", false);

        // Defining 'Program' class... 
        TypeBuilder programClass = module.DefineType(
            "MathClient.Program",
            TypeAttributes.Public | TypeAttributes.Class); 

        // Defining Main() method... 
        MethodBuilder mainMethod = programClass.DefineMethod(
            "Main",
            MethodAttributes.Public | MethodAttributes.Static,
            null, 
            new Type[] { typeof(string[]) });
        ILGenerator mainMethodILGenerator = mainMethod.GetILGenerator();
        LocalBuilder aLocalVariable = mainMethodILGenerator.DeclareLocal(typeof(int), true);
        mainMethodILGenerator.Emit(OpCodes.Ldc_I4, 10);
        mainMethodILGenerator.Emit(OpCodes.Stloc, aLocalVariable);      // a = 10 

        // List 'a' value... 
        mainMethodILGenerator.Emit(OpCodes.Ldstr, "a = {0}");
        mainMethodILGenerator.Emit(OpCodes.Ldloc, aLocalVariable);
        mainMethodILGenerator.Emit(OpCodes.Box, typeof(int));
        Type consoleType = typeof(System.Console);
        MethodInfo writeLineMethod = consoleType.GetMethod(
            "WriteLine",
            new Type[] { typeof(string), typeof(object) });
        mainMethodILGenerator.Emit(OpCodes.Call, writeLineMethod);

        mainMethodILGenerator.Emit(OpCodes.Ret);

        // Bake 'Program' class type... 
        programClass.CreateType(); 

        // Set Main() method as an entry point...
        assembly.SetEntryPoint(mainMethod, PEFileKinds.ConsoleApplication);

        // Optionally save to disk...
        //assembly.Save("MathClient.exe");
    }

When I'm trying to execute the assembly in a default application domain

    static void Main(string[] args)
    {
        AppDomain currentDomain = AppDomain.CurrentDomain; 

        // Create new assembly in memory... 
        CreateMathClient(currentDomain);

        // Execute 'MathClient.exe' in the current domain... 
        currentDomain.ExecuteAssemblyByName(
            "MathClient,Version=1.0.0.0,Culture=neutral,PublicKeyToken=null");

        Console.ReadLine();
    }

the following exception is throwing

System.IO.FileNotFoundException was unhandled HResult=-2147024894 Message=Could not load file or assembly 'MathClient, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.

However, if the assembly was preliminary saved to disk

        // Optionally save to disk...
        assembly.Save("MathClient.exe");

everything works perfectly fine.
Why can't I execute the assembly with ExecuteAssemblyByName()?